SEACOR Marine (SMHI) 10-K 29 Feb 24 2023 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Feb. 25, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Trading Symbol	SMHI
Entity Registrant Name	SEACOR Marine Holdings Inc.
Entity Central Index Key	0001690334
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Title of 12(b) Security	Common stock
Security Exchange Name	NYSE
Entity File Number	1-37966
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-2564547
Entity Address, Address Line One	12121 Wickchester Lane
Entity Address, Address Line Two	Suite 500
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77079
City Area Code	346
Local Phone Number	980-1700
Document Annual Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		27,178,349
Entity Public Float			$ 272.5
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Document financial statement error correction	false
Auditor Firm ID	248
Auditor Name	GRANT THORNTON LLP
Auditor Location	Houston, Texas
Documents Incorporated by Reference	Portions of the Registrant’s definitive proxy statement for its 2024 Annual Meeting of Stockholders to be filed with the Securities and Exchange Commission (the “SEC”) pursuant to Regulation 14A within 120 days after the end of the Registrant’s last fiscal year is incorporated by reference into Part III of this Annual Report on Form 10-K.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents		$ 67,455	$ 39,963
Restricted cash		16,676	3,082
Receivables:
Trade, net of allowance for credit loss accounts of $4,543 and $1,650 in 2023 and 2022, respectively		63,728	54,388
Other		11,049	7,375
Note receivable		0	15,000
Tax receivable		983	578
Inventories		1,609	2,123
Prepaid expenses and other		2,686	3,054
Assets held for sale		500	6,750
Total current assets		164,686	132,313
Property and Equipment:
Historical cost	[1]	918,823	967,683
Accumulated depreciation		(324,141)	(310,778)
Property and equipment		594,682	656,905
Construction in progress		10,362	8,111
Net property and equipment		605,044	665,016
Right-of-use asset - operating leases		4,291	6,206
Right-of-use asset - finance leases		37	6,813
Investments, at equity, and advances to 50% or less owned companies		4,125	3,024
Other assets		2,153	1,995
Total assets		780,336	815,367
Current Liabilities:
Current portion of operating lease liabilities		1,591	2,358
Current portion of finance lease liabilities		35	468
Current portion of long-term debt:
Recourse		28,365	61,512
Accounts payable and accrued expenses		27,562	37,955
Accrued wages and benefits		5,083	4,361
Accrued interest		1,850	2,305
Accrued capital, repair and maintenance expenditures		2,471	2,748
Unearned revenue		687	2,333
Accrued insurance deductibles and premiums		3,189	2,428
Other current liabilities		6,253	4,694
Total current liabilities		77,086	121,162
Long-term operating lease liabilities		3,529	4,739
Long-term finance lease liabilities		6	6,781
Long-term Debt:
Recourse		287,544	254,653
Non-recourse		0	5,466
Deferred income taxes		35,718	40,779
Deferred gains and other liabilities		2,229	2,641
Total liabilities		406,112	436,221
SEACOR Marine Holdings Inc. stockholders' equity:
Common stock, $.01 par value, 60,000,000 shares authorized; 27,665,792 and 26,950,799 shares issued in 2023 and 2022, respectively		280	272
Additional paid-in capital		472,692	466,669
Accumulated deficit		(102,425)	(93,111)
Shares held in treasury of 481,014 and 248,638 in 2023 and 2022, respectively, at cost		(4,221)	(1,852)
Accumulated other comprehensive income, net of tax		7,577	6,847
Total stockholders equity		373,903	378,825
Noncontrolling interests in subsidiaries		321	321
Total equity		374,224	379,146
Total liabilities and equity		$ 780,336	$ 815,367
[1] Includes property and equipment acquired in business acquisitions at acquisition date fair value and net of the impact of recognized impairment charges. Some of the Company’s vessels are pledged as security for certain loans.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Trade receivables, allowance for credit loss	$ 4,543	$ 1,650
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	60,000,000	60,000,000
Common stock, shares issued (in shares)	27,665,792	26,950,799
Shares held in treasury (in shares)	481,014	248,638

Consolidated Statements of Inco

Consolidated Statements of Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Operating Revenues	$ 279,511	$ 217,325	$ 170,941
Costs and Expenses:
Operating	159,650	171,985	127,406
Administrative and general	49,183	40,911	37,639
Lease expense	2,748	3,869	6,085
Depreciation and amortization	53,821	55,957	57,395
Costs and expenses	265,402	272,722	228,525
Gains on Asset Dispositions and Impairments, Net	21,409	1,398	20,436
Operating Income (Loss)	35,518	(53,999)	(37,148)
Other Income (Expense):
Interest income	1,444	784	1,302
Interest expense	(37,504)	(29,706)	(28,111)
SEACOR Holdings guarantee fees	0	0	(7)
(Losses) Gains on debt extinguishment	(2,004)	10,429	61,994
Derivative gains, net	608	0	391
Foreign currency gains (losses), net	(2,133)	1,659	(1,235)
Gain from return of investments in 50% or less owned companies and other, net	0	755	9,441
Nonoperating income (expense)	(39,589)	(16,079)	43,775
(Loss) Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	(4,071)	(70,078)	6,627
Income Tax Expense:
Current	13,860	8,485	6,633
Deferred	(5,061)	97	4,860
Income tax expense	8,799	8,582	11,493
Loss from Continuing Operations Before Equity in Earnings of 50% or Less Owned Companies	(12,870)	(78,660)	(4,866)
Equity in Earnings of 50% or Less Owned Companies	3,556	7,011	15,078
(Loss) Income from Continuing Operations	(9,314)	(71,649)	10,212
Income on Discontinued Operations, Net of Tax (see Note 18)	0	0	22,925
Net (Loss) Income	(9,314)	(71,649)	33,137
Net Income attributable to Noncontrolling Interests in Subsidiaries	0	1	1
Net (Loss) Income attributable to SEACOR Marine Holdings Inc.	$ (9,314)	$ (71,650)	$ 33,136
Net (Loss) Earnings Per Share from Continuing Operations:
Basic	$ (0.34)	$ (2.69)	$ 0.40
Diluted	(0.34)	(2.69)	0.40
Net Earnings Per Share from Discontinued Operations:
Basic	0	0	0.90
Diluted	0	0	0.90
Net (Loss) Earnings Per Share:
Basic	(0.34)	(2.69)	1.30
Diluted	$ (0.34)	$ (2.69)	$ 1.30
Weighted Average Common Shares and Warrants Outstanding:
Basic	27,082,391	26,626,179	25,444,693
Diluted	27,082,391	26,626,179	25,495,527

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Net (Loss) Income	$ (9,314)	$ (71,649)	$ 33,137
Other Comprehensive Income (Loss):
Foreign currency translation gains (losses), net	1,245	(4,451)	3,986
Derivative gains (losses) on cash flow hedges	56	1,608	219
Other comprehensive income	730	(1,208)	5,265
Income tax expense	0	0	0
Other comprehensive income, net	730	(1,208)	5,265
Comprehensive (Loss) Income	(8,584)	(72,857)	38,402
Comprehensive Income Attributable to Noncontrolling Interests in Subsidiaries	0	1	1
Comprehensive (Loss) Income Attributable to SEACOR Marine Holdings Inc.	(8,584)	(72,858)	38,401
Interest Expense
Other Comprehensive Income (Loss):
Reclassification of derivative (gains) losses on cash flow hedges to interest expense	(571)	694	1,648
Equity Method Investments
Other Comprehensive Income (Loss):
Reclassification of derivative (gains) losses on cash flow hedges to interest expense	$ 0	$ 941	$ (588)

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Reclassification of derivative gains (losses) on cash flow hedges to equity in losses	50%	50%	50%

Consolidated Statements of Chan

Consolidated Statements of Changes In Equity - USD ($) $ in Thousands		Total		Director [Member]	Common Stock [Member]	Common Stock [Member] Director [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member] Director [Member]	Treasury Stock [Member]	Treasury Stock [Member] Director [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Income [Member]	Non-Controlling Interests In Subsidiaries [Member]
Balance at Dec. 31, 2020		$ 401,836			$ 235		$ 451,179		$ (848)		$ (51,839)	$ 2,790	$ 319
Balance (in shares) at Dec. 31, 2020					23,430,766				73,284
Restricted stock grants		8			$ 8
Restricted stock grants (in shares)					815,550
Forfeiture of employee share awards (in shares)					(5,250)
Amortization of share awards		$ 5,002					5,002
Exercise of options (in shares)	[1]	0
Exercise of warrants		$ 1			$ 1
Exercise of Warrants (in shares)					48,809
Restricted stock vesting		(272)							$ (272)
Restricted stock vesting (in shares)					(54,603)				54,603
Director share awards				$ 437		$ 2		$ 435
Director share awards (in shares)						189,030
Acquisition of 50% or less owned company		5,331			$ 16		5,315
Acquisition of 50% or less owned company (in shares)					1,567,935
Sale of Windcat Workboats		(4,204)									(4,204)
Net (Loss) Income		33,137									33,136		1
Other comprehensive income		5,265										5,265
Balance at Dec. 31, 2021		446,541			$ 262		461,931		$ (1,120)		(22,907)	8,055	320
Balance (in shares) at Dec. 31, 2021					25,992,237				127,887
Restricted stock grants		9			$ 9
Restricted stock grants (in shares)					738,896
Forfeiture of employee share awards (in shares)					(3,500)
Amortization of share awards		4,587					4,587
Exercise of options		$ 151					151
Exercise of options (in shares)		34,492	[1]		34,492
Restricted stock vesting		$ (672)		(60)					$ (672)	$ (60)
Restricted stock vesting (in shares)					(114,251)	(6,500)			114,251	6,500
Director share awards				1		$ 1
Director share awards (in shares)						60,787
Net (Loss) Income		(71,649)									(71,650)		1
Other comprehensive income		238									1,446	(1,208)
Balance at Dec. 31, 2022		$ 379,146			$ 272		466,669		$ (1,852)		(93,111)	6,847	321
Balance (in shares) at Dec. 31, 2022		26,950,799			26,702,161				248,638
Issuance of common stock		$ 24					24
Issuance of Common Stock (in shares)					7,674
Restricted stock grants		6			$ 6
Restricted stock grants (in shares)					525,397
Forfeiture of employee share awards (in shares)					(15,000)
Amortization of share awards		5,993					5,993
Exercise of options		$ 6					6
Exercise of options (in shares)		834	[1]		834
Exercise of warrants					$ 1				$ (1)
Exercise of Warrants (in shares)					135,013				137
Restricted stock vesting		$ (2,368)							$ (2,368)
Restricted stock vesting (in shares)					(232,239)				232,239
Director share awards				$ 1		$ 1
Director share awards (in shares)						60,938
Net (Loss) Income		(9,314)									(9,314)
Other comprehensive income		730										730
Balance at Dec. 31, 2023		$ 374,224			$ 280		$ 472,692		$ (4,221)		$ (102,425)	$ 7,577	$ 321
Balance (in shares) at Dec. 31, 2023		27,665,792			27,184,778				481,014
[1] The intr insic value of the options exercised was less than $ 0.1 million.

Consolidated Statements of Ch_2

Consolidated Statements of Changes In Equity (Parenthetical)	Dec. 31, 2021
Maximum
Ownership Percentage	50%

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash Flows from Continuing Operating Activities:
Net (Loss) Income	$ (9,314,000)	$ (71,649,000)	$ 33,137,000
Adjustments to reconcile net (loss) income to net cash provided by (used in) operating activities:
Depreciation and amortization	53,821,000	55,957,000	57,395,000
Deferred financing cost amortization	1,579,000	8,000	1,097,000
Stock-based compensation expense	6,000,000	4,597,000	5,447,000
Debt discount amortization	6,761,000	6,693,000	6,866,000
Allowance for credit losses	3,519,000	489,000	863,000
Gain from equipment sales, retirements or impairments	(21,409,000)	(1,398,000)	(20,436,000)
Gain on the sale of Windcat Workboats	0	0	(22,756,000)
Gain from return of investments in 50% or less owned companies	0	0	(9,442,000)
Loss (gain) on debt extinguishment	177,000	(12,700,000)	(62,749,000)
Derivative gains	(608,000)	0	(391,000)
Interest on finance lease	202,000	244,000	4,000
Settlement on derivative transactions, net	577,000	(749,000)	(2,150,000)
Currency losses (gains)	2,133,000	(1,659,000)	1,235,000
Deferred income taxes	(5,061,000)	97,000	4,860,000
Equity earnings	(3,556,000)	(7,011,000)	(15,078,000)
Dividends received from equity investees	2,241,000	3,057,000	5,332,000
Changes in Operating Assets and Liabilities:
Accounts receivables	(17,215,000)	(652,000)	22,437,000
Other assets	2,288,000	2,559,000	3,113,000
Accounts payable and accrued liabilities	(13,188,000)	7,501,000	471,000
Net cash provided by (used in) operating activities	8,947,000	(14,616,000)	9,255,000
Cash Flows from Continuing Investing Activities:
Purchases of property and equipment	(10,604,000)	(462,000)	(7,003,000)
Proceeds from disposition of property and equipment	44,730,000	6,734,000	30,137,000
Proceeds from sale of Windcat Workboats, net of transaction costs and cash sold	0	0	38,715,000
Investments in and advances to 50% or less owned companies	0	0	(3,008,000)
Excess distributions from equity investees	0	0	9,442,000
Principal payments on notes due from equity investees	0	528,000	3,345,000
Cash received from acquisition of 50% or less owned company	0	0	172,000
Proceeds from sale of investment in equity investees	0	66,000,000	0
Notes due from others	0	(28,831,000)	0
Principal payments on notes due from others	15,000,000	13,831,000	0
Net cash provided by investing activities	49,126,000	57,800,000	71,800,000
Cash Flows from Continuing Financing Activities:
Payments on long-term debt	(29,165,000)	(38,152,000)	(78,124,000)
Payments on debt extinguishment	(131,604,000)	0	0
Payments on debt extinguishment costs	(1,827,000)	(2,271,000)	(755,000)
Proceeds from issuance of long-term debt, net of issue costs	148,475,000	0	0
Proceeds from issuance of common stock, net of issue costs	24,000	0	0
Proceeds from exercise of stock options and warrants	6,000	151,000	1,000
Payments on finance lease	(531,000)	(351,000)	(30,000)
Tax withholdings on restricted stock vesting and director share awards	(2,368,000)	(732,000)	(272,000)
Net cash used in financing activities	(16,990,000)	(41,355,000)	(79,180,000)
Effects of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash	3,000	(4,000)	(22,000)
Net Change in Cash, Cash Equivalents and Restricted Cash, Continuing Operations	41,086,000	1,825,000	1,853,000
Cash Flows from Discontinued Operations:
Operating Activities	0	0	(171,000)
Investing Activities	0	0	0
Financing Activities	0	0	0
Effects of Exchange Rate Changes on Cash, Restricted Cash and Cash Equivalents	0	0	0
Net Change in Cash, Restricted Cash and Cash Equivalents on Discontinued Operations	0	0	(171,000)
Net Change in Cash, Cash Equivalents and Restricted Cash	41,086,000	1,825,000	1,682,000
Cash, Cash Equivalents and Restricted Cash, Beginning of Year	43,045,000	41,220,000	39,538,000
Cash, Cash Equivalents and Restricted Cash, End of Year	84,131,000	43,045,000	41,220,000
Supplemental disclosures:
Cash paid for interest, excluding capitalized interest	31,446,000	25,244,000	24,143,000
Income taxes (paid) refunded, net	(2,961,000)	885,000	32,759,000
Noncash Investing and Financing Activities:
Distribution from equity investee	0	0	2,538,000
Acquisition of 50% or less owned company	0	0	23,037,000
Increase in long-term debt related to asset purchases	0	0	6,500,000
Decrease in debt related to debt settlement	0	0	62,749,000
Increase in capital expenditures in accounts payable and accrued liabilities	371,000	0	10,379,000
Exchange of property and equipment	0	8,918,000	0
Recognition of a new right-of-use asset - operating leases	499,000	2,363,000	3,582,000
Recognition of a new right-of-use asset - finance leases	$ 0	$ 7,248,000	$ 0

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net Income (Loss)	$ (9,314)	$ (71,650)	$ 33,136

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2023 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	During the fourth quarter of 2023, none of our directors or Section 16 officers adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement” (as each term is defined in Item 408(a) of Regulation S-K), except as set forth in the table below: Name and Title Action Date Type of Trading Arrangement (1) Duration of Trading Arrangement (2) Aggregate Number of Securities to be Sold pursuant to Trading Arrangement Andrew H. Everett II , Senior Vice President, General Counsel and Secretary Adoption November 8, 2023 Rule 10b5-1 trading arrangement November 8, 2024 Up to 31,694 shares of Common Stock Jesús Llorca , Executive Vice President and Chief Financial Officer Adoption November 8, 2023 Rule 10b5-1 trading arrangement March 3, 2025 Up to 182,712 shares of Common Stock (3) Gregory Rossmiller , Senior Vice President and Chief Accounting Officer Adoption November 13, 2023 Rule 10b5-1 trading arrangement March 3, 2025 Up to 58,852 shares of Common Stock John Gellert , President and Chief Executive Officer Adoption November 21, 2023 Rule 10b5-1 trading arrangement March 14, 2025 Up to 67,848 shares of Common Stock (1) Each trading arrangement marked as a “Rule 10b5-1 trading arrangement” is intended to satisfy the affirmative defense of Rule 10b5-1(c). (2) Each trading arrangement permits transactions through and including the earlier to occur of (i) the completion of all sales under the trading arrangement and (ii) the date listed in the table. (3) Mr. Llorca’s Rule 10b5-1 trading arrangement provides for the potential sale of up to (i) 84,795 shares of Common Stock and (ii) 97,917 shares of Common Stock issuable upon the exercise of options to acquire shares of Common Stock.
Andrew H. Everett II
Trading Arrangements, by Individual
Name	Andrew H. Everett II
Title	Senior Vice President, General Counsel and Secretary
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	November 8, 2023
Aggregate Available	31,694
Expiration Date	November 8, 2024
Jesus Llorca
Trading Arrangements, by Individual
Name	Jesús Llorca
Title	Executive Vice President and Chief Financial Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	November 8, 2023
Aggregate Available	182,712
Expiration Date	March 3, 2025
Gregory Rossmiller
Trading Arrangements, by Individual
Name	Gregory Rossmiller
Title	Senior Vice President and Chief Accounting Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	November 13, 2023
Aggregate Available	58,852
Expiration Date	March 3, 2025
John Gellert
Trading Arrangements, by Individual
Name	John Gellert
Title	President and Chief Executive Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	November 21, 2023
Aggregate Available	67,848
Expiration Date	March 14, 2025
Directors or Section 16 Officers
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Rule 10b51 Arr Potential Sale of Shares [Member] | Jesus Llorca
Trading Arrangements, by Individual
Aggregate Available	84,795
Rule10b51Arr Stock Issuable Upon Exercise Of Option [Member] | Jesus Llorca
Trading Arrangements, by Individual
Aggregate Available	97,917

Nature of Operations and Accoun

Nature of Operations and Accounting Policies	12 Months Ended
	Dec. 31, 2023
Nature Of Operation And Accounting Policies [Abstract]
Nature of Operations and Accounting Policies	1. NATURE OF OPERATIONS AND ACCOUNTING POLICIES Nature of Operations and Segmentation. The consolidated financial statements include the accounts of SEACOR Marine Holdings Inc. (“SEACOR Marine”), and its consolidated subsidiaries (collectively referred to as the “Company”). The Company provides global marine and support transportation services to offshore energy facilities worldwide. The Company operates and manages a diverse fleet of offshore support vessels that (i) deliver cargo and personnel to offshore installations, including offshore wind farms, (ii) assist offshore operations for production and storage facilities, (iii) provide construction, well work-over, offshore wind farm installation and decommissioning support, (iv) carry and launch equipment used underwater in drilling and well installation, maintenance, inspection and repair and (v) handle anchors and mooring equipment for offshore rigs and platforms. Additionally, the Company's vessels provide emergency response services and accommodations for technicians and specialists. Accounting standards require public business enterprises to report information about each of their operating business segments that exceed certain quantitative thresholds or meet certain other reporting requirements. Operating business segments have been defined as a component of an enterprise about which separate financial information is available and is evaluated regularly by the chief operating decision maker in assessing performance. Upon the Company’s sale of Windcat Workboats Holdings Limited (“Windcat Workboats”) on January 12, 2021, the Company’s European operations were no longer analyzed by the chief operating decision maker on a standalone basis but rather as part of the Africa and Europe segment. As a result, for purposes of segment reporting, European operations are now combined with the Africa segment and reported as a combined segment and prior period information has been conformed to the new consolidated reporting segment. The Company has identified the following four principal geographic regions as its reporting segments: United States, primarily Gulf of Mexico. As of December 31, 2023 , 13 vessels were located in this region, including 11 owned and two managed. The Company’s vessels in this market support oil and natural gas exploration and production activities, seasonal construction, decommissioning and diving support operations, as well as the construction and maintenance of offshore wind farms in the Northeast of the U.S. Africa and Europe, continuing operations. As of December 31, 2023 , 19 vessels were located in this region, including 18 owned and one leased-in. The Company’s vessels in this market generally support projects for major oil companies, primarily in Angola, Nigeria and the North Sea. Middle East and Asia. As of December 31, 2023 , 16 vessels were located in this region, including 15 owned and one managed . The Company’s vessels in this area generally support exploration, personnel transport and seasonal construction activities in Saudi Arabia, United Arab Emirates, Qatar, Egypt and Israel. Latin America. As of December 31, 2023 , ten owned vessels were located in this region. The Company’s vessels in this area generally provide support for exploration and production activities primarily in Mexico, Guyana and Trinidad and Tobago. From time to time, the Company’s vessels also work in Brazil and Colombia. Basis of Consolidation. The consolidated financial statements include the accounts of SEACOR Marine and its controlled subsidiaries. Control is generally deemed to exist if the Company has greater than 50 % of the voting rights of a subsidiary. All significant intercompany accounts and transactions are eliminated in the combination and consolidation. Noncontrolling interests in consolidated subsidiaries are included in the consolidated balance sheets as a separate component of equity. The Company reports consolidated net income (loss) inclusive of both the Company’s and the noncontrolling interests’ share, as well as the amounts of consolidated net income (loss) attributable to each of the Company and the noncontrolling interests. If a subsidiary is deconsolidated upon a change in control, any retained noncontrolling equity investment in the former controlled subsidiary is measured at fair value and a gain or loss is recognized in net income (loss) based on such fair value. If a subsidiary is consolidated upon the business acquisition of controlling interests by the Company, any previous noncontrolled equity investment in the subsidiary is measured at fair value and a gain or loss is recognized in net income (loss) based on such fair value. The Company employs the equity method of accounting for investments in 50% or less owned companies that it does not control but has the ability to exercise significant influence over the operating and financial policies of the business venture. Significant influence is generally deemed to exist if the Company has between 20 % and 50 % of the voting rights of a business venture but may exist when the Company’s ownership percentage is less than 20%. In certain circumstances, the Company may have an economic interest in excess of 50% but may not control and consolidate the business venture. Conversely, the Company may have an economic interest less than 50% but may control and consolidate the business venture. The Company reports its investments in and advances to these business ventures in the accompanying consolidated balance sheets as investments, at equity, and advances to 50% or less owned companies. The Company reports its share of earnings from investments in 50% or less owned companies in the accompanying consolidated statements of income (loss) as equity in earnings of 50% or less owned companies, net of tax. Certain reclassifications were made to previously reported amounts in the consolidated financial statements and notes thereto to make them consistent with the current period presentation. Use of Estimates. The preparation of financial statements in conformity with accounting principles generally accepted in the United States (“U.S.”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from estimates and those differences may be material. Revenue Recognition. The Company contracts with various customers to carry out management services for vessels as agents for and on behalf of ship owners. These services include crew management, technical management, commercial management, insurance arrangements, sale and purchase of vessels, provisions and bunkering. As the manager of the vessels, the Company undertakes to use its best endeavors to provide the agreed management services as agents for and on behalf of the owners in accordance with sound ship management practice and to protect and promote the interest of the owners in all matters relating to the provision of services thereunder. The Company also contracts with various customers to carry out management services regarding engineering for vessel construction and vessel conversions. The vast majority of the ship management agreements span one to three years and are typically billed on a monthly basis. The Company transfers control of the service to the customer and satisfies its performance obligation over the term of the contract, and therefore recognizes revenue over the term of the contract while related costs are expensed as incurred. Revenue that does not meet these criteria is deferred until the criteria is met and is considered a contract liability and is recognized as such. Contract liabilities, which are included in unearned revenue in the accompanying consolidated balance sheets, for the years ended December 31 were as follows (in thousands): 2023 2022 2021 Balance at beginning of year $ 2,333 $ 1,606 $ 4,452 Unearned revenues during the year 6,501 4,288 10,167 Revenues recognized during the year ( 8,147 ) ( 3,561 ) ( 13,013 ) Balance at end of year $ 687 $ 2,333 $ 1,606 As of December 31, 2023, December 31, 2022 and December 31, 2021 , the Company had unearned revenue of $ 0.7 million, $ 2.3 million and $ 1.6 million, respectively, primarily related to mobilization of vessels. The Company earns revenue primarily from the time charter and bareboat charter of vessels to customers. Since the Company charges customers based upon daily rates of hire, vessel revenues are recognized on a daily basis throughout the contract period. Under a time charter, the Company provides a vessel to a customer and is responsible for all operating expenses, typically excluding fuel. Under a bareboat charter, the Company provides a vessel to a customer and the customer assumes responsibility for all operating expenses and assumes all risks of operation. In the U.S. Gulf of Mexico, time charter durations and rates are typically established in the context of master service agreements that govern the terms and conditions of the charter. In the Company’s operating areas, contracts or charters vary in length from several days to multi-year periods. Many of the Company’s contracts and charters include cancellation clauses without early termination penalties. As a result of cancellations, options and frequent renewals, the stated duration of charters may not correlate with the length of time the vessel is contracted for to provide services to a particular customer. During the year ended December 31, 2023, the Company recognized an aggregate amount of business interruption insurance recoveries of $ 6.5 million included in operating revenues in the accompanying consolidated statements of income (loss). Direct Operating Expenses. Direct operating costs and expenses, other than leased-in expense, consist primarily of costs such as personnel; repairs and maintenance; drydocking; insurance and loss reserves; fuel, lubes and supplies; and other vessel expenses, which include costs such as brokers’ commissions, communication costs, expenses incurred in mobilizing vessels between geographic regions, third party ship management fees, freight expenses, and customs and importation duties. Direct operating costs are expensed as incurred. Cash Equivalents. The Company considers all highly liquid investments, with an original maturity of three months or less from the date purchased, to be cash equivalents. Cash equivalents consist of U.S. treasury securities, money market instruments, time deposits and overnight investments. A portion of the Company’s cash is maintained at federally insured financial institutions. The deposits held at these institutions are in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institution in which those deposits are held. Restricted Cash. Restricted cash primarily relates to banking facility requirements. For the years ended December 31, cash, cash equivalents and restricted cash consists of: 2023 2022 Cash $ 67,455 $ 39,963 Restricted cash 16,676 3,082 Total $ 84,131 $ 43,045 Trade and Other Receivables and Allowance for Credit Losses. Customers are primarily major integrated national, international oil companies, large independent oil and natural gas exploration and production companies and established wind farm construction companies. Customers are granted credit on a short-term basis and the related credit risks are minimal. Other receivables consist primarily of operating expenses the Company incurs in relation to vessels it manages for other entities, as well as insurance and income tax receivables, but excludes our short-term note receivable. The Company routinely reviews its receivables and makes provisions for expected credit losses utilizing the Current Expected Credit Losses model (“CECL”). The CECL model utilizes a lifetime expected credit loss measurement objective for the recognition of credit losses for loans and other receivables at the time the financial asset is originated or acquired. However, those provisions are estimates and actual results may materially differ from those estimates. Trade receivables that are deemed uncollectible and are removed from accounts receivable and the allowance for credit losses when collection efforts have been exhausted. Derivative Instruments. The Company accounts for derivatives through the use of a fair value concept whereby all of the Company’s derivative positions are stated at fair value in the accompanying consolidated balance sheets. Realized and unrealized gains and losses on derivatives not designated as hedges are reported in the accompanying consolidated statements of income (loss) as Derivative gains (losses), net. Realized and unrealized gains and losses on derivatives designated as fair value hedges are recognized as corresponding increases or decreases in the fair value of the underlying hedged item to the extent they are effective, with any ineffective portion reported in the accompanying consolidated statements of income (loss) as Derivative gains (losses), net, and related cash flows are classified in the same category on the cash flow statement as the cash flows from the items being hedged. Realized and unrealized gains and losses on derivatives designated as cash flow hedges are reported as a component of other comprehensive income (loss) in the accompanying consolidated statements of comprehensive income (loss) to the extent they are effective and reclassified into earnings on the same line item associated with the hedged transaction and in the same period the hedged transaction affects earnings and related cash flows are classified in the same category on the cash flow statement as the cash flows from the items being hedged. Any ineffective portions of cash flow hedges are reported in the accompanying consolidated statements of income (loss) as Derivative gains (losses), net. Realized and unrealized gains and losses on derivatives designated as cash flow hedges that are entered into by the Company’s 50% or less owned companies are also reported as a component of the Company’s other comprehensive income (loss) in proportion to the Company’s ownership percentage, with reclassifications and ineffective portions being included in Equity in earnings of 50% or less owned companies, net of tax, in the accompanying consolidated statements of income (loss). Concentrations of Credit Risk. The Company is exposed to concentrations of credit risk associated with its cash and cash equivalents, restricted cash and derivative instruments. The Company minimizes its credit risk relating to these positions by monitoring the financial condition of the financial institutions and counterparties involved and by primarily conducting business with large, well-established financial institutions and diversifying its counterparties. The Company does not currently anticipate nonperformance by any of its significant counterparties. The Company is also exposed to concentrations of credit risk relating to its receivables due from customers described above. The Company does not generally require collateral or other security to support its outstanding receivables. The Company minimizes its credit risk relating to receivables by performing ongoing credit evaluations and, to date, credit losses have not been material. Inventories. Inventories, which consist of fuel and supplies, are stated at the lower of cost (using the first-in, first-out method) or net realizable value. The Company records write-downs, as needed, to adjust the carrying amount of inventories to the lower of cost or net realizable value. In the years ended December 31, 2023, 2022 and 2021 , there were no inventory reserves. Property and Equipment. Equipment, stated at cost, is depreciated using the straight-line method over the estimated useful life of the asset to an estimated salvage value. With respect to each class of asset, the estimated useful life is based upon a newly built asset being placed into service and represents the time period beyond which it is typically not justifiable for the Company to continue to operate the asset in the same or similar manner. From time to time, the Company may acquire older vessels that have already exceeded the Company’s useful life policy, in which case the Company depreciates such assets based on its best estimate of remaining useful life, typically the next survey or certification date. As of December 31, 2023 , the estimated useful life of the Company’s new offshore support vessels was 20 years. The Company’s property and equipment as of December 31 was as follows (in thousands): Historical (1) Accumulated Net Book 2023 Offshore support vessels: AHTS (2) $ 12,112 $ ( 4,578 ) $ 7,534 FSV (3) 340,411 ( 142,096 ) 198,315 PSV (4) 301,461 ( 53,100 ) 248,361 Liftboats 243,295 ( 103,459 ) 139,836 General machinery and spares 9,343 ( 9,161 ) 182 Other (5) 12,201 ( 11,747 ) 454 $ 918,823 $ ( 324,141 ) $ 594,682 2022 Offshore support vessels: AHTS (2) $ 27,281 $ ( 18,139 ) $ 9,142 FSV (3) 354,473 ( 130,599 ) 223,874 PSV (4) 295,875 ( 36,112 ) 259,763 Specialty 3,163 ( 3,138 ) 25 Liftboats 264,142 ( 102,156 ) 161,986 General machinery and spares 10,148 ( 8,565 ) 1,583 Other (5) 12,601 ( 12,069 ) 532 $ 967,683 $ ( 310,778 ) $ 656,905 (1) Includes property and equipment acquired in business acquisitions at acquisition date fair value and net of the impact of recognized impairment charges. Some of the Company’s vessels are pledged as security for certain loans. (2) Anchor Handling Towing Supply vessels (“AHTS”). (3) Fast support vessels (“FSVs”). (4) Platform support vessels (“PSVs”). (5) Includes buildings, leasehold improvements, vehicles and other property and equipment. Depreciation and amortization expense totaled $ 53.8 million, $ 56.0 million and $ 57.4 million in 2023, 2022 and 2021 , respectively. There was no depreciation and amortization expense from discontinued operations in 2023, 2022 or 2021. Equipment maintenance and repair costs and the costs of routine overhauls, drydockings and inspections performed on vessels and equipment are charged to operating expense as incurred. Expenditures that extend the useful life or improve the marketing and commercial characteristics of equipment as well as major renewals and improvements to other properties are capitalized. Certain interest costs incurred during the construction of equipment are capitalized as part of the assets’ carrying values and are amortized over such assets’ estimated useful lives. There was no capitalized interest recognized in 2023 or 2022 . Capitalized interest totaled $ 0.3 million in 2021 . Assets Held for Sale. As of December 31, 2023 , one AHTS previously included in the Africa and Europe segment, with a carrying value of $ 0.5 million, was classified as assets held for sale as the Company expects to sell the vessel within one year. Impairment of Long-Lived Assets. The Company performs an impairment analysis of long-lived assets used in operations when indicators of impairment are present. These indicators may include a significant decrease in the market price of a long-lived asset or asset group, a significant adverse change in the extent or manner in which a long-lived asset or asset group is being used or in its physical condition, or a current period operating or cash flow loss combined with a history of operating or cash flow losses or a forecast that demonstrates continuing losses associated with the use of a long-lived asset or asset group. If the carrying values of the assets are not recoverable, as determined by their estimated future undiscounted cash flows, the estimated fair value of the assets or asset groups are compared to their current carrying values and impairment charges are recorded if the carrying value exceeds fair value. As a result of the difficult conditions experienced in the offshore oil and natural gas markets beginning in the second half of 2014 and the corresponding reductions in utilization and rates per day worked of its fleet, the Company identified indicators of impairment and recognized impairment charges primarily associated with its AHTS fleet, its liftboat fleet, certain specialty vessels and vessels removed from service. When reviewing its fleet for impairment, the Company groups vessels with similar operating and marketing characteristics, including cold-stacked vessels expected to return to active service, into vessel classes. All other vessels, including vessels retired and removed from service, are evaluated for impairment on a vessel by vessel basis. During the year ended December 31, 2023 , the Company recorded impairment charges totaling $ 0.7 million for one leased-in AHTS to adjust for indicative future cash flows and the cost to return the vessel to its owner. During the year ended December 31, 2022 , the Company recorded impairment charges totaling $ 2.9 million. The Company recorded impairment charges of $ 0.9 million for one FSV classified as held for sale and sold during 2022. In addition, the Company recorded impairment charges of $ 0.7 million for one leased-in AHTS as it is not expected to return to active service during its remaining lease term. Additionally, the Company recorded impairment charges of $ 1.3 million for other equipment and classified such equipment as assets held for sale as the Company expects to sell the equipment within one year. The impairment charges for the assets held for sale are included in (losses) gains on asset dispositions and impairments in the accompanying consolidated statements of income (loss). There were no impairments of other owned or leased-in vessels. The Company’s other vessel classes and other individual vessels in active service and cold-stacked status, for which no impairment was deemed necessary, have generally experienced a less severe decline in utilization and rates per day worked based on specific market factors. The market factors include vessels with more general utility to a broad range of customers (e.g., FSVs), vessels required for customers to meet regulatory mandates and operating under multiple year contracts or vessels that service customers outside of the offshore oil and natural gas market. For vessel classes and individual vessels with indicators of impairment as of December 31, 2023, the Company estimated that their future undiscounted cash flows exceeded their current carrying values. However, the Company’s estimates of future undiscounted cash flows are highly subjective as utilization and rates per day worked are uncertain, especially in light of the continued volatility in commodity prices as well as the timing and cost of reactivating cold-stacked vessels. If market conditions decline, changes in the Company’s expectations on future cash flows may result in recognizing additional impairment charges related to its long-lived assets in future periods. For any vessel or vessel class that has indicators of impairment and is deemed not recoverable through future operations, the Company determines the fair value of the vessel or vessel class. If the fair value determination is less than the carrying value of the vessel or vessel class, an impairment is recognized to reduce the carrying value to fair value. Fair value determination is primarily accomplished by obtaining independent valuations of vessel or vessel classes from qualified third party appraisers. Impairment of 50% or Less Owned Companies. Investments in 50% or less owned companies are reviewed periodically to assess whether there is an other-than-temporary decline in the carrying value of the investment. In its evaluation, the Company considers, among other items, recent and expected financial performance and returns, impairments recorded by the investee and the capital structure of the investee. When the Company determines the estimated fair value of an investment is below carrying value and the decline is other-than-temporary, the investment is written down to its estimated fair value. Actual results may vary from the Company’s estimates due to the uncertainty regarding projected financial performance, the severity and expected duration of declines in value and the available liquidity in the capital markets to support the continuing operations of the investee, among other factors. Although the Company believes its assumptions and estimates are reasonable, the investee’s actual performance compared with the estimates could produce different results and lead to additional impairment charges in future periods. No impairment charges of investments in 50% or less owned companies were incurred for the years ended December 31, 2023, 2022 and 2021 . Business Combinations. For acquisitions constituting a business acquisition, the Company recognizes 100% of the fair value of assets acquired, liabilities assumed, and noncontrolling interests when the acquisition constitutes a change in control of the acquired entity. Shares issued in consideration for a business combination, contingent consideration arrangements and pre-acquisition loss and gain contingencies are all measured and recorded at their acquisition-date fair value. Subsequent changes to fair value of contingent consideration arrangements are generally reflected in earnings. Acquisition-related transaction costs are expensed as incurred and any changes in an acquirer’s existing income tax valuation allowances and tax uncertainty accruals are recorded as an adjustment to income tax expense. The operating results of entities acquired are included in the accompanying consolidated statements of income (loss) from the date of acquisition. If an acquisition of an asset or group of assets does not meet the definition of a business, the transaction is accounted for as an asset acquisition. The assets are measured based on their cost to the Company, including transaction costs. The acquisition cost is then allocated to the assets acquired based on their relative fair values. Debt Discount and Issue Costs . Debt discounts and costs incurred in connection with the issuance of debt are amortized over the life of the related debt using the effective interest rate method for term loans and straight-line method for revolving credit facilities and are included in interest expense in the accompanying consolidated statements of income (loss). Self-insurance Liabilities . The Company maintains marine hull, liability and war risk, general liability, workers compensation and other insurance customary in the industry in which it operates. Both the marine hull and liability policies have annual aggregate deductibles. Marine hull annual aggregate deductibles are accrued as claims are incurred while marine liability annual aggregate deductibles are accrued based on historical loss experience. Exposure to the health benefit plans are limited by maintaining stop-loss and aggregate liability coverage. To the extent that estimated self-insurance losses, including the accrual of annual aggregate deductibles, differ from actual losses realized, the Company’s insurance reserves could differ significantly and may result in either higher or lower insurance expense in future periods. Income Taxes . Deferred income tax assets and liabilities have been provided in recognition of the income tax effect attributable to the book and tax basis differences of assets and liabilities reported in the consolidated financial statements. Deferred tax assets or liabilities are provided using the enacted tax rates expected to apply to taxable income in the periods in which they are expected to be settled or realized. Interest and penalties relating to uncertain tax positions are recognized in interest expense and administrative and general, respectively, in the accompanying consolidated statements of income (loss). The Company records a valuation allowance to reduce its deferred tax assets if it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Global Intangible Low Taxed Income (“GILTI”) regime effectively imposes a minimum tax on worldwide foreign earnings and subjects U.S. shareholders of controlled foreign corporations (“CFCs”) to current taxation on certain income earned through a CFC. The Company has made the policy election to record any liability associated with GILTI in the period in which it is incurred. In the normal course of business, the Company may be subject to challenges from tax authorities regarding the amount of taxes due for the Company. These challenges may alter the timing or amount of taxable income or deductions. As part of the calculation of income tax expense, the Company determines whether the benefits of its tax positions are at least more likely than not of being sustained based on the technical merits of the tax position. For tax positions that are more likely than not of being sustained, the Company accrues the largest amount of the tax benefit that is more likely than not of being sustained. Such accruals require management to make estimates and judgments with respect to the ultimate outcome of its tax benefits and actual results could vary materially from these estimates. Foreign Currency Translation. The assets, liabilities and results of operations of certain consolidated subsidiaries are measured using their functional currency, which is the currency of the primary foreign economic environment in which they operate. Upon consolidating these subsidiaries with the Company, their assets and liabilities are translated to U.S. dollars at currency exchange rates as of the consolidated balance sheet dates and their revenues and expenses are translated at the weighted average currency exchange rates during the applicable reporting periods. Translation adjustments resulting from the process of translating these subsidiaries’ financial statements are reported in other comprehensive income in the accompanying consolidated statements of comprehensive income (loss). Foreign Currency Transactions. Certain consolidated subsidiaries enter into transactions denominated in currencies other than their functional currency. Gains and losses resulting from changes in currency exchange rates between the functional currency and the currency in which a transaction is denominated are included in foreign currency losses, net in the accompanying consolidated statements of income (loss) in the period in which the currency exchange rates change. Accumulated Other Comprehensive (Loss) Income. The components of accumulated other comprehensive (loss) income were as follows (in thousands): SEACOR Marine Holdings Inc. Noncontrolling Interests Foreign Derivative (Losses) Gains on Cash Flow Total Foreign Derivative Other Year Ended December 31, 2020 $ 6,797 $ ( 4,007 ) $ 2,790 $ ( 1,445 ) $ ( 11 ) $ 1,242 Other comprehensive income 3,986 1,279 5,265 — — 5,265 Income tax (expense) — — — — — — Year Ended December 31, 2021 10,783 ( 2,728 ) 8,055 ( 1,445 ) ( 11 ) $ 5,265 Other comprehensive loss ( 4,451 ) 3,243 ( 1,208 ) — — $ ( 1,208 ) Income tax benefit (expense) — — — — — — Year Ended December 31, 2022 6,332 515 6,847 ( 1,445 ) ( 11 ) $ ( 1,208 ) Other comprehensive income 1,245 ( 515 ) 730 — — 730 Income tax benefit (expense) — — — — — — Year Ended December 31, 2023 $ 7,577 $ — $ 7,577 $ ( 1,445 ) $ ( 11 ) $ 730 Earnings (Loss) Per Share. Basic earnings/loss per share of the common stock, par value $ 0.01 per share, of SEACOR Marine (“Common Stock”) is computed based on the weighted average number of shares of Common Stock and warrants to purchase Common Stock at an exercise price of $ 0.01 per share (“Warrants”) issued and outstanding during the relevant periods. The Warrants are included in the basic earnings/loss per share of Common Stock because the shares issuable upon exercise of the Warrants are issuable for de minimis cash consideration and therefore not anti-dilutive. Diluted earnings/loss per share of Common Stock is computed based on the weighted average number of shares of Common Stock and Warrants issued and outstanding plus the effect of other potentially dilutive securities through the application of the treasury stock method and the if-converted method that assumes all shares of Common Stock have been issued and outstanding during the relevant periods pursuant to the conversion of the Old Convertible Notes and the New Convertible Notes (as defined in “Note 6. Long-Term Debt”) unless

Note Receivable

Note Receivable	12 Months Ended
	Dec. 31, 2023
Receivables [Abstract]
Note Receivable	2. NOTE RECEIVABLE In connection with the closing of the Framework Agreement Transactions (as defined in “Note 4. Investments, at Equity and Advances to 50% or Less Owned Companies”), on September 29, 2022, SEACOR Marine Capital Inc., a wholly owned subsidiary of the Company (“SEACOR Marine Capital”) purchased all of the outstanding loans under the Second Amended and Restated Term Loan Credit Facility Agreement, made as of July 8, 2022, by and among Mantenimiento Express Marítimo, S.A.P.I. de C.V. (“MexMar”), as the borrower, DNB Capital LLC and The Governor and Company of the Bank of Ireland, each as lenders, and DNB Bank ASA, New York Branch, as facility agent (as amended from time to time, the “MexMar Original Facility Agreement”) for an aggregate amount of $ 28.8 million, representing par value of the loan using proceeds received from the Framework Agreement Transactions. On the same date, the MexMar Original Facility Agreement was amended and restated in the MexMar Third A&R Facility Agreement pursuant to which, among other things, (i) MexMar repaid approximately $ 8.8 million of the outstanding loan amount and (ii) agreed to repay the $ 20.0 million of the loan that remained outstanding by September 30, 2023 through four quarterly installments of $ 5.0 million. As of December 31, 2023 , the loan balance due from MexMar was repaid in full.

Equipment Acquisitions and Disp

Equipment Acquisitions and Dispositions	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Equipment Acquisitions and Dispositions	3. EQUIPMENT ACQUISITIONS AND DISPOSITIONS Equipment Additions. The Company’s capital expenditures and payments on equipment were $ 10.6 million, $ 0.5 million, and $ 7.0 million in 2023, 2022 and 2021 , respectively. Deliveries of offshore support vessels for the years ended December 31 were as follows: 2023 2022 2021 (1) FSV 1 — — PSV — 1 1 1 1 1 (1) Excludes five PSVs acquired as part of the OSV Partners Acquisition in 2021. Equipment Dispositions During the year ended December 31, 2023, the Company sold one liftboat, classified as held for sale, three liftboats and one specialty vessel, previously removed from service, one FSV and other equipment, previously classified as held for sale, as well as other equipment not previously classified as such, for net cash proceeds of $ 44.7 million, after transaction costs, and a gain of $ 21.1 million. During the year ended December 31, 2022, the Company sold one FSV, one liftboat previously removed from service, office space and other equipment for net cash proceeds of $ 6.7 million, after transaction costs, and a gain of $ 2.2 million, which included impairment charges of $ 0.9 million for one FSV classified as held for sale and sold during 2022. During the year ended December 31, 2021, the Company sold one PSV, three FSVs and reduced $ 22.5 million of debt under the FGUSA Credit Facility (as defined and described in Note 7. Long-Term Debt) with hull and machinery insurance proceeds received in respect of the SEACOR Power of $ 25.0 million, for a total of $ 30.1 million in consideration and gains of $ 20.9 million. Major equipment dispositions for the years ended December 31 were as follows: 2023 2022 (1) 2021 (2) AHTS — 1 — FSV 1 1 3 PSV — — 1 Liftboats 4 1 1 Specialty 1 — — 6 3 5 (1) Excludes one specialty vessel that was previously removed from service, which was sold in 2023. (2) Excludes four liftboats that were previously removed from service, of which three were sold in 2023 and one was sold in 2022. On January 12, 2021, a wholly owned subsidiary of the Company, completed the sale of the Company’s Windcat Workboats crew transfer vessel (“CTV”) business through the sale of 100% of the equity of Windcat Workboats, a wholly owned subsidiary of the Company (“Windcat” and together with its subsidiaries, the “Windcat Group”), to CMB N.V. (the “Windcat Buyer”) pursuant to a Sale and Purchase Agreement entered into on December 18, 2020. At closing, the Windcat Buyer paid to the Company an aggregate purchase price of £32.8 million. After deducting transaction costs and expenses and giving effect to foreign exchange rate hedges, the Company received net cash proceeds of approximately $42.6 million. The Windcat Buyer also assumed all of the approximately £20.4 million of debt outstanding under Windcat Workboat’s existing revolving credit facility. As of December 31, 2020, the Windcat Group owned a total of 41 CTVs and held interests in an additional five CTVs through its joint ventures, all of which were included in the sale. The Company recognized a gain on the sale of Windcat Workboats of approximately $22.8 million during 2021, calculated as follows: (In Thousands): January 12, 2021 Total Proceeds Received $ 43,797 Transactions Fees and other Costs 1,562 Cash Sold 3,520 Total Net Proceeds 38,715 Less: Net Equity in Windcat Workboats, net of cash sold 15,790 Less: January Income on Discontinued Operations 169 Gain on Sale of Windcat Workboats $ 22,756

Investments, at Equity, and Adv

Investments, at Equity, and Advances to 50% or Less Owned Companies	12 Months Ended
	Dec. 31, 2023
Schedule of Investments [Abstract]
Investments, at Equity, and Advances to 50% or Less Owned Companies	4. INVESTMENTS, AT EQUITY, AND ADVANCES TO 50% OR LESS OWNED COMPANIES Investments, at equity, and advances to 50% or less owned companies as of December 31 were as follows (in thousands): Ownership 2023 2022 Seabulk Angola 49.0 % 1,668 1,683 SEACOR Marine Arabia 45.0 % 2,385 1,265 Other 20.0 % — 50.0 % 72 76 $ 4,125 $ 3,024 Combined Condensed Financial Information of Other Investees. Summarized financial information of the Company’s other investees, at equity, as of and for the years ended December 31 was as follows (in thousands): 2023 2022 Current assets $ 29,820 $ 24,699 Noncurrent assets 61 266 Current liabilities 21,008 17,070 Noncurrent liabilities — — 2023 2022 2021 Operating Revenues $ 68,949 $ 133,740 $ 156,579 Costs and Expenses: Operating and administrative 61,294 90,678 139,313 Depreciation 27 21,434 23,524 61,321 112,112 162,837 Operating Income (Loss) $ 7,628 $ 21,628 $ ( 6,258 ) Net Income $ 5,239 $ 15,057 $ 41,798 As of December 31, 2023 , cumulative undistributed net earnings of all 50% or less owned companies included in the Company’s consolidated retained earnings were $ 2.8 million. MexMar, OVH and SEACOR Marlin. On September 29, 2022, SEACOR Marine and certain of its subsidiaries, on the one hand, and Operadora de Transportes Marítimos, S.A. de C.V. (“OTM”), CME Drillship Holdings DAC (“CME Ireland”), and Offshore Vessels Holding, S.A.P.I. de C.V. (“OVH”), on the other hand, entered into a Framework Agreement (the “Framework Agreement”). OTM and CME Ireland are affiliates of Proyectos Globales de Energía y Servicios CME, S.A. de C.V. (“CME”). Alfredo Miguel Bejos is the President and Chief Executive Officer of CME and also serves as a member of SEACOR Marine’s board of directors (“Board of Directors”). Prior to the closing of the Framework Agreement Transactions (defined below), the Company owned 49 % of each of MexMar and OVH through SEACOR Marine International LLC, a wholly owned subsidiary of the Company (“SEACOR Marine International”), and the remaining 51 % ownership interests were held by OTM. The Company also owned a minority interest in SEACOR Marlin LLC (“SEACOR Marlin LLC”), the owner of the PSV SEACOR Marlin, and the remaining ownership interests of SEACOR Marlin LLC were held by MexMar. The Framework Agreement provided for, among other things, (i) the sale by SEACOR Marine LLC, a wholly owned subsidiary of the Company (“SMLLC”), of all of the outstanding equity interests of SEACOR Marine International to OTM for a purchase price of $ 66.0 million in cash, (ii) the sale of the AHTS SEACOR Davis to CME Ireland in exchange for the remaining equity interests in SEACOR Marlin LLC, such that SEACOR Marlin LLC became a wholly owned subsidiary of the Company, (iii) the transfer of a hybrid battery power system from OVH to SEACOR Marine Capital as repayment in full of a certain vessel loan agreement provided by the Company to its former joint venture, and (iv) entry into a bareboat charter agreement between SEACOR Marlin LLC and MexMar (collectively, the “Framework Agreement Transactions”). Each of the Framework Agreement Transactions was consummated on September 29, 2022. As a result of the Framework Agreement Transactions, the Company no longer owns any equity interest in either MexMar or in OVH, and the Company owns all of the equity interests in SEACOR Marlin LLC, which owns the PSV SEACOR Marlin. Accordingly, the Company does not currently operate any joint-ventured vessels, which prior to the transactions were comprised solely of the 19 offshore support vessels owned by MexMar and OVH and the one PSV owned by SEACOR Marlin LLC. The vessel owned by SEACOR Marlin LLC became wholly owned in the transaction. The Company recognized a gain on the sale of MexMar, OVH and other assets of approximately $ 0.8 million, calculated as follows: September 29, 2022 Total Cash Received $ 66,000 51% ownership in SEACOR Marlin Joint Venture 7,000 Hybrid Battery Power System 1,394 Less: Transaction Fees and other Costs 1,159 Total Net Proceeds 73,235 Less: Net Equity in MexMar and OVH Joint Ventures 65,546 Less: Net Book Value of SEACOR Davis 5,507 Less: OVH Note Receivable 1,394 Gain on Sale of MexMar, OVH and Other Assets $ 788 MexMar Management Fees. During the years ended December 31, 2022 and 2021, there were no returns of capital advances or distributions to shareholders and the Company charged $ 0.2 million and $ 0.3 million, respectively of vessel management fees to MexMar. OSV Partners. On December 31, 2021, SEACOR Marine, SEACOR Offshore OSV LLC, a wholly owned subsidiary of the Company (“SEACOR Offshore OSV”) and SEACOR OSV Partners I LP, a Delaware limited partnership (“OSV Partners I”), entered into a certain merger agreement (“OSV Partners Merger Agreement”) pursuant to which OSV Partners I merged with and into SEACOR Offshore OSV, with SEACOR Offshore OSV surviving the merger (the “OSV Partners Merger”). The results of operations of OSV Partners are included in net income (loss) in the “Combined Condensed Financial Information of Other Investees” for the year ended December 31, 2021 for the whole period as the entity was consolidated upon completion of the acquisition. SEACOR Marlin LLC. SEACOR Marlin LLC owns the PSV SEACOR Marlin. On September 13, 2018, the Company sold 51 % of SEACOR Marlin LLC to MEXMAR Offshore (MI) LLC, a wholly owned subsidiary of MexMar, for $ 8.0 million in cash, which generated a gain of $ 0.4 million. As a result of the Framework Agreement Transactions, the Company owns all of the equity interests in SEACOR Marlin LLC. The results of operations of SEACOR Marlin LLC are included in net income (loss) in the “Combined Condensed Financial Information of Other Investees” for the year ended December 31, 2021 and for the portion of 2022 that the entity was a 50% or less owned company. During the years ended December 31, 2022 and 2021, there was a distribution to the Company of $ 1.1 million and $ 2.5 million, respectively. MEXMAR Offshore – UP Offshore Sale Transaction . On June 1, 2021, MEXMAR Offshore International LLC (“MEXMAR Offshore”), a joint venture 49 % owned by an indirect wholly owned subsidiary of the Company, and 51 % owned by a subsidiary of Proyectos Globales de Energía y Servicios CME, S.A. de C.V. (“CME”), UP Offshore (Bahamas) Ltd. (“UP Offshore”), a provider of offshore support vessel services to the energy industry in Brazil and a wholly owned subsidiary of MEXMAR Offshore, and certain subsidiaries of UP Offshore, completed the sale of eight vessels and certain Brazilian entities to OceanPact Servícos Marítimos S.A. and its subsidiary, OceanPact Netherlands B.V., for a total purchase price of $ 30.2 million (the “UP Offshore Sale Transaction”). The UP Offshore Sale Transaction resulted in an equity earnings gain from 50 % or less owned companies of $ 2.6 million. MEXMAR Offshore – Distribution and Winddown . On July 23, 2021, the Company received a distribution from MEXMAR Offshore in connection with the UP Offshore Sale Transaction in the amount of $ 12.0 million of which $ 9.4 million was in excess of the Company’s investment balance of $ 2.6 million. The excess was recorded by the Company in the third quarter as a gain from return of investments in 50% or less owned companies. After giving effect to the UP Offshore Sale Transaction, MEXMAR Offshore, indirectly through certain subsidiaries of UP Offshore, retained ownership of three vessels. As part of the winddown of the MEXMAR Offshore joint venture, ownership of two of these vessels was transferred from subsidiaries of UP Offshore to OVH on October 26, 2021, and the remaining vessel was transferred from a subsidiary of UP Offshore to OVH on November 2, 2021. Upon completion of these transactions, MEXMAR Offshore no longer held income producing assets and as a result, on December 9, 2021, the Company transferred its 49 % interest in MEXMAR Offshore to a subsidiary of CME for nominal consideration and a transaction fee of $ 0.2 million. As of December 31, 2021, the Company does not have any ownership interest in MEXMAR Offshore. The results of operations of MexMar Offshore are included in net income (loss) in the “Combined Condensed Financial Information of Other Investees” for the year ended December 31, 2021 for the period the entity was a 50% or less owned company. OVH. On December 28, 2018, the Company invested $ 4.9 million for a 49 % interest in OVH. The remaining 51 % is owned by a subsidiary of CME. OVH invests in offshore assets and charters marine equipment. During the year ended December 31, 2019 OVH loaned $ 10.0 million to Operadora Productora y Exploradora Mexicana S.A. de C.V., a drilling company in Mexico and affiliate of CME which owns and operates two jackup drilling rigs (“OPEM”), chartered-in three PSVs from UP Offshore (a subsidiary of MEXMAR Offshore) and purchased one FSV from the Company for $ 2.4 million through a seller’s finance agreement. As part of the winddown of the MEXMAR Offshore joint venture, ownership of two of these PSVs was transferred from UP Offshore to OVH on October 26, 2021, and the remaining PSV was transferred from UP Offshore to OVH on November 2, 2021. On December 10, 2021, OVH and OPEM settled the $ 10.0 million loan in exchange for OPEM making an early repayment of $ 10.5 million, reflecting repayment of the principal amount in full and a prepayment discount and forgiveness of approximately $ 4.1 million of accrued interest. As a result of the Framework Agreement Transactions discussed above, the Company no longer owns any equity interest in OVH. The Company charged no management fees to OVH for the year ended 2022 and charged $ 1.0 million of management fees to OVH for the year ended 2021. SEACOR Marine Arabia LLC (“SEACOR Marine Arabia”) and other. The Company’s other 50% or less owned companies do not own or operate any vessels. During the years ended December 31, 2023, 2022 and 2021 , the Company received dividends of $ 2.2 million, $ 2.0 million and $ 2.0 million from these 50% or less owned companies, respectively. During the years ended December 31, 2023, 2022 and 2021 , no vessel management fees were received from these 50% or less owned companies.

Leases

Leases	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Leases	5. LEASES The Company assesses at contract inception whether a contract is, or contains, a lease, defined as a contract that conveys the right to control the use of an identified asset for a period of time in exchange for consideration. In calculating the present value of lease payments, the Company uses its incremental borrowing rate at the lease commencement date when the interest rate implicit in the lease is not readily determinable and includes the Company’s assessment and impact of any extensions, escalations or special terms. The Company applies the short-term lease recognition exemption to its short-term leases of machinery and equipment (i.e., those leases that have a lease term of 12 months or less from the commencement date and do not contain a purchase option). It also applies the lease of low-value assets recognition exemption to leases of office equipment that are considered to be low value. As of December 31, 2023 , the Company leased-in one AHTS and certain facilities and other equipment. The leases typically contain purchase and renewal options or rights of first refusal with respect to the sale or lease of the equipment. As of December 31, 2023 , the lease terms of the vessel had a remaining duration of nine months . The lease terms of certain facilities and other equipment range in duration from two to 276 months. As of December 31, 2023, future minimum payments for leases for the years ended December 31 were as follows (in thousands): Operating Leases Finance Leases 2024 $ 1,864 $ 36 2025 746 6 2026 459 — 2027 400 — 2028 341 — Years subsequent to 2028 2,873 — 6,683 42 Interest component ( 1,563 ) ( 1 ) 5,120 41 Current portion of long-term lease liabilities 1,591 35 Long-term lease liabilities $ 3,529 $ 6 For the years ended December 31, the components of lease expense were as follows (in thousands): 2023 2022 Operating lease costs $ 2,222 $ 3,162 Finance lease costs: Amortization of finance lease asset (1) 468 545 Interest on lease liabilities (2) 202 246 Short-term lease costs 526 707 $ 3,418 $ 4,660 (1) Included in amortization costs in the consolidated statements of income (loss). (2) Included in interest expense in the consolidated statements of income (loss). For the year ended December 31, 2023, supplemental cashflow information related to leases were as follows (in thousands): 2023 Operating cash flows from operating leases $ 2,362 Financing cash outflows from finance leases 531 Right-of-use assets obtained for operating lease liabilities 499 Right-of-use assets obtained for finance lease liabilities — For the year ended December 31, 2023, other information related to leases were as follows: 2023 Weighted average remaining lease term, in years - operating leases 10.2 Weighted average remaining lease term, in years - finance leases 1.2 Weighted average discount rate - operating leases 6.7 % Weighted average discount - finance leases 4.0 % The Company recorded impairment losses of $ 0.7 million for one such lease in the year ended December 31, 2023 and $ 0.7 million for one such lease in the year ended December 31, 2022. The Company recorded no impairment losses for the leased offshore support vessels for the year ended December 31, 2021.

Long Term Debt

Long Term Debt	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Long Term Debt	6. LONG-TERM DEBT The Company’s long-term debt obligations as of December 31 were as follows (in thousands): 2023 2022 Recourse long-term debt (1) : Guaranteed Notes $ 90,000 $ 90,000 New Convertible Notes 35,000 35,000 2023 SMFH Credit Facility (2) 118,950 — 2018 SMFH Credit Facility (2) — 67,910 Sea-Cat Crewzer III Term Loan Facility 14,227 16,703 SEACOR Delta Shipyard Financing (3) 68,647 77,537 SEACOR Alpine Credit Facility (4) 26,200 — SEACOR Alpine Shipyard Financing (4) — 27,790 SEACOSCO Acquisition Debt (2) — 16,205 SEACOR 88/888 Term Loan (2) — 5,500 Tarahumara Shipyard Financing (2) — 5,597 SEACOR Offshore OSV (2) — 16,052 Total recourse long-term debt 353,024 358,294 Non-recourse long-term debt (5) : SEACOR 88/888 Term Loan (2) — 5,500 Total non-recourse long-term debt — 5,500 Total principal due for long-term debt 353,024 363,794 Current portion due within one year ( 28,365 ) ( 61,512 ) Unamortized debt discount ( 32,885 ) ( 37,511 ) Deferred financing costs ( 4,230 ) ( 4,652 ) Long-term debt, less current portion $ 287,544 $ 260,119 (1) Recourse debt represents debt issued by SEACOR Marine and/or its subsidiaries and guaranteed by SEACOR Marine or one of its operating subsidiaries as provided in the relevant debt agreements. (2) Proceeds from the 2023 SMFH Credit Facility, dated September 8, 2023, were used to satisfy in full the 2018 SMFH Credit Facility, the SEACOSCO Acquisition Debt, the SEACOR 88/888 Term Loan, the Tarahumara Shipyard Financing, and the SEACOR Offshore OSV debt. See details below. (3) SEACOR Delta Shipyard Financing includes vessel financing on the eight SEACOR Delta PSVs. See details below. (4) Proceeds from the SEACOR Alpine Credit Facility, dated June 16, 2023, were used to satisfy in full the SEACOR Alpine Shipyard Financing. See details below. (5) Non-recourse debt represents debt issued by one of the Company’s consolidated subsidiaries with no recourse to SEACOR Marine or its other non-obligor operating subsidiaries with respect to the applicable instrument, other than certain limited support obligations as provided in the respective debt agreements, which in aggregate are not considered to be material to the Company’s business and financial condition. The Company’s contractual long-term debt maturities from continuing operations for the years ended December 31 were as follows (in thousands): 2024 $ 28,365 2025 28,605 2026 152,405 2027 27,165 2028 110,257 Years subsequent to 2028 6,227 $ 353,024 As of December 31, 2023, the Company was in compliance with all debt covenants and lender requirements. The Carlyle Investment. On December 1, 2015, the Company issued $ 175.0 million in aggregate principal amount of its convertible senior notes due 2023 (the “Old Convertible Notes”), at an annual interest rate of 3.75 %, initially due December 1, 2022, (subsequently amended to December 2, 2023 as described below) to certain funds affiliated with The Carlyle Group Inc. (“Carlyle” and such funds, the “Carlyle Investors”). The Old Convertible Notes were convertible into shares of Common Stock at a conversion rate of 23.26 shares per $ 1,000 in principal amount of such notes, subject to certain conditions, or, into warrants to purchase an equal number of shares of Common Stock at an exercise price of $ 0.01 per share in order to facilitate the Company’s compliance with the provisions of the Jones Act. The Company bifurcated the embedded conversion option liability of $ 27.3 million from the Old Convertible Notes and recorded an additional debt discount (see “Note 8. Derivative Instruments and Hedging Strategies” and “Note 9. Fair Value Measurements”). The adjusted unamortized debt discount and issue costs of the Old Convertible Notes were amortized as additional non-cash interest expense over the remaining term of the debt for an overall effective interest rate of 7.95 % and the changes in the fair value of the bifurcated derivative were recorded as derivative income or loss. On May 2, 2018, the Company and the Carlyle Investors entered into an exchange transaction (the “Exchange”) pursuant to which Carlyle Investors exchanged $ 50.0 million in principal amount of the Old Convertible Notes for Warrants to purchase 1,886,792 shares of Common Stock (to facilitate compliance with the provisions of the Jones Act) at an exercise price of $ 0.01 per share, subject to adjustments (the “Carlyle Warrants”), representing an implied exchange rate of approximately 37.73 shares per $ 1,000 in principal amount of the Old Convertible Notes (equivalent to an exchange price of $ 26.50 per share). The Carlyle Warrants have a 25 -year term, which commenced May 2, 2018. The Company and Carlyle Investors also amended the $ 125.0 million in principal amount of Old Convertible Notes that remained outstanding following the Exchange to (i) increase the interest rate from 3.75 % per annum to 4.25 % per annum and (ii) extend the maturity date of the Old Convertible Notes by 12 months to December 1, 2023. The adjusted unamortized debt discount and issue costs of the Old Convertible Notes were amortized as additional non-cash interest expense over the remaining term of the debt for an overall effective interest rate of 9.29 % and the changes in the fair value of the bifurcated derivative were recorded as derivative income or loss. On October 5, 2022, SEACOR Marine and the Carlyle Investors entered into two agreements pursuant to which SEACOR Marine issued the Carlyle Investors (i) $ 90.0 million in aggregate principal amount of the Company’s 8.0 % / 9.5 % Senior PIK Toggle Notes due 2026 (the “Guaranteed Notes”) and (ii) $ 35.0 million aggregate principal amount of SEACOR Marine’s 4.25 % Convertible Senior Notes due 2026 (the “New Convertible Notes”) in exchange for all of SEACOR Marine’s Old Convertible Notes (the “Exchange Transactions”). During the year ended December 31, 2022, the Company recognized contractual interest expense of $ 4.0 million and amortization of debt discount and issue costs of $ 4.0 million, for total interest expense of $ 8.0 million. Guaranteed Notes. The Guaranteed Notes were issued pursuant to the Exchange Agreement (Guaranteed Notes) among SEACOR Marine, as issuer, Falcon Global Robert LLC, a wholly owned subsidiary of the Company (“FG Robert”), as the guarantor, and the Carlyle Investors (the “Guaranteed Notes Exchange Agreement”). Pursuant to the Guaranteed Notes Exchange Agreement, SEACOR Marine has the right to pay interest on the Guaranteed Notes (i) in cash at a rate of 8.0 % per annum (“Cash Interest”) or (ii) partly in cash and partly in-kind by increasing the principal amount of the Guaranteed Notes or issuing additional Guaranteed Notes at a rate of 9.5 % per annum (“Hybrid Interest”) with the cash portion of the Hybrid Interest bearing interest at a rate of 4.25 % per annum and in the in-kind portion of the Hybrid Interest bearing interest at a rate of 5.25 % per annum. The Guaranteed Notes mature on July 1, 2026. The Guaranteed Notes are guaranteed on a senior unsecured basis by FG Robert, the owner of the LB Robert liftboat. SEACOR Marine may redeem some or all of the Guaranteed Notes at any time in minimum denominations of $ 10.0 million, upon not less than 30 nor more than 60 calendar days’ notice, at a price equal to (a) 101 % of the principal amount of the Guaranteed Notes redeemed, if redeemed prior to October 1, 2024 and (b) 100 % of the principal amount of the Guaranteed Notes redeemed, if redeemed on or after October 1, 2024, in either case plus accrued and unpaid interest, if any, to, but not including, the redemption date, provided, SEACOR Marine may not redeem the Guaranteed Notes if the principal amount of Guaranteed Notes and New Convertible Notes outstanding will be equal to or less than $ 50.0 million in the aggregate, unless SEACOR Marine redeems all of the Guaranteed Notes in whole. The Guaranteed Notes Exchange Agreement contains certain customary covenants that among others, limit the ability of (i) SEACOR Marine and FG Robert to incur indebtedness, (ii) FG Robert to create or incur liens, (iii) SEACOR Marine to create liens on the ownership interest of FG Robert, (iv) FG Robert to sell assets, and (v) SEACOR Marine to sell the ownership interest of FG Robert, as well as customary representations and warranties made by SEACOR Marine, FG Robert and the Carlyle Investors and customary events of default. New Convertible Notes. The New Convertible Notes were issued pursuant to the Exchange Agreement (Convertible Notes) among SEACOR Marine, as issuer, and the Carlyle Investors (the “Convertible Notes Exchange Agreement”). The New Convertible Notes bear interest at a rate of 4.25 % per annum payable semi-annually in arrears and mature on July 1, 2026 . The New Convertible Notes are convertible into shares of Common Stock at the option of the holders at a conversion rate of 85.1064 shares per $ 1,000 in principal amount of New Convertible Notes (equivalent to a “Conversion Price” of $ 11.75 ) or into warrants to purchase an equal number of shares of Common Stock at an exercise price of $ 0.01 per share in order to facilitate SEACOR Marine’s compliance with the provisions of the Jones Act. In addition, SEACOR Marine has the right to cause the mandatory conversion of the New Convertible Notes into Common Stock if the daily volume-weighted average price (“VWAP”) of the Common Stock equals or exceeds (A) in the case of New Convertible Notes held by affiliates of Carlyle, 150 % of the Conversion Price and (B) in the case of New Convertible Notes held by any Person other than affiliates of Carlyle, 115 % of the Conversion Price, in each case for each of the 20 consecutive trading days. If SEACOR Marine undergoes a Company Fundamental Change (as defined in the Convertible Notes Exchange Agreement), the holders of the New Convertible Notes may require SEACOR Marine to purchase for cash all or part of the New Convertible Notes at a price equal to 100 % of the principal amount the New Convertible Notes to be purchased, plus accrued and unpaid interest to the date of purchase. The New Convertible Notes may be redeemed, in whole but not in part and only if certain conditions are met, as more fully described in the Convertible Notes Exchange Agreement, at a price equal to 100 % of the principal amount of the New Convertible Notes to be redeemed, plus accrued and unpaid interest to the date of redemption. Under the Convertible Notes Exchange Agreement, the Carlyle Investors have the ability to nominate one director to the Board of Directors but currently do not exercise this right. The Convertible Notes Exchange Agreement contains customary representations and warranties made by SEACOR Marine and the Carlyle Investors and contains customary events of default and covenants. The conversion option of the New Convertible Notes qualified as an exception from the derivative accounting treatment under Accounting Standards Codification 815. Accordingly, the conversion option was not bifurcated and the debt was recorded at fair value. The adjusted unamortized debt discount and issue costs are being amortized as additional non-cash interest expense over the remaining term of the New Convertible Notes for an overall effective interest rate of 9.46 %. As of December 31, 2023, the unamortized discount and issue costs were $ 3.7 million and $ 0.4 million, respectively, for a total net carrying amount of $ 30.9 million. In addition, during the year ended December 31, 2023, the Company recognized contractual interest expense of $ 2.9 million and amortization of debt discount and issue costs of $ 1.4 million, for total interest expense of $ 4.3 million. As of December 31, 2022, the unamortized discount and issue costs were $ 4.9 million and $ 0.6 million, respectively, for a total net carrying amount of $ 29.5 million. In addition, during the year ended December 31, 2022, the Company recognized contractual interest expense of $ 0.7 million and amortization of debt discount and issue costs of $ 0.3 million, for total interest expense of $ 1.0 million. 2023 SMFH Credit Facility. On September 8, 2023, SEACOR Marine, as parent guarantor, SEACOR Marine Foreign Holdings Inc. (“SMFH”), as borrower, and certain other wholly owned subsidiaries of SEACOR Marine, as subsidiary guarantors, entered into a credit agreement providing for a $ 122.0 million senior secured term loan (the “2023 SMFH Credit Facility”) with certain affiliates of EnTrust Global, as lenders, Kroll Agency Services, Limited, as facility agent, and Kroll Trustee Services Limited, as security trustee for the purposes of creating a more rational and efficient capital structure for the Company by consolidating a number of different credit facilities with different lending groups into a single facility. The proceeds of the 2023 SMFH Credit Facility were used to: (x) refinance approximately $ 104.8 million of existing principal indebtedness comprised of: (a) $ 61.1 million incurred under the 2018 SMFH Credit Facility (as defined below), (b) $ 11.0 million incurred under the SEACOR 88/888 Term Loan (as defined below), (c) $ 15.1 million incurred under the SEACOR OSV Credit Facility (as defined below), (d) $ 13.7 million incurred under the SEACOSCO Acquisition Debt (as defined below), and (e) $ 3.9 million incurred under the Tarahumara Shipyard Financing (as defined below), which payoff amount reflects a 7 % discount to book value, (y) acquire 100 % ownership of the Amy Clemons McCall, a 2014 built FSV, previously operated under lease and now pledged as collateral under the 2023 SMFH Credit Facility, and (z) satisfy accrued and unpaid interest, fees, and general corporate purposes. The funds available under the 2023 SMFH Credit Facility were fully drawn on September 14, 2023. The 2023 SMFH Credit Facility matures on September 14, 2028, with quarterly amortization of 2.5 % of the initial loan advanced thereunder, with the remaining outstanding principal amount due on the maturity date. The 2023 SMFH Credit Facility bears interest at a fixed rate of 11.75 % per annum. The loan may be prepaid at any time in amounts of $ 1,000,000 or greater, subject to: (a) prior to the 12-month anniversary of funding, a premium equal to the remaining unpaid interest due over the first 15 months of the loan, and (b) after the 12-month anniversary of funding and prior to the 30-month anniversary of funding, a decreasing premium ranging from 3.00 % to 1.00 % of the amount prepaid . The 2023 SMFH Credit Facility contains customary covenants for financings of this type including financial maintenance and restrictive covenants, such as the aggregate collateral vessel value to the sum of the outstanding principal amounts of the loans. The 2023 SMFH Credit Facility restricts the payment of dividends and distributions and the ability of the borrower and subsidiary guarantors to make certain investments, subject to important exceptions. In addition, the 2023 SMFH Credit Facility includes customary events of default. SEACOR Marine issued a guaranty with respect to the obligations of the Borrower under the 2023 SMFH Credit Facility and related documents (the “2023 SMFH Credit Facility Guaranty”). The 2023 SMFH Credit Facility Guaranty includes, among other customary covenants, various financial covenants, including (A) minimum Cash and Cash Equivalents (as defined in the 2023 SMFH Credit Facility) of the greater of $ 20.0 million and 7.5 % of Net Interest-Bearing Debt (as defined in the 2023 SMFH Credit Facility), (B) minimum Equity Ratio (as defined in the 2023 SMFH Credit Facility) of 35 %, and (C) maximum Debt-to-Capitalization Ratio (as defined in the 2023 SMFH Credit Facility) of 65 %. The Company was in compliance with all such covenants as of December 31, 2023. The 2023 SMFH Credit Facility Guaranty also restricts the payment of dividends and distributions and includes certain restrictions on the prepayment of unsecured indebtedness. During the year ended December 31, 2023, the Company expensed $ 1.8 million of payments for early terminations fees and $ 0.2 million of unamortized debt issue costs related to the debt extinguishment. 2018 SMFH Credit Facility. On September 26, 2018, SMFH, a wholly owned subsidiary of the Company, entered into a $ 130.0 million loan facility with a syndicate of lenders administered by DNB Bank ASA (as amended from time to time, the “2018 SMFH Credit Facility”) that was secured by mortgages on certain vessels owned by the Company’s vessel owning subsidiaries as well as an assignment of earnings from those subsidiaries. The obligations of SMFH under the 2018 SMFH Credit Facility were guaranteed by SEACOR Marine (as amended from time to time, the “2018 SMFH Credit Facility Guaranty”). Principal payments of $ 3.3 million per quarter under the 2018 SMFH Credit Facility began in December 2018. As amended on September 29, 2022, the 2018 SMFH Credit Facility and 2018 SMFH Credit Facility Guaranty provided for, among other things, (i) a $ 5.3 million prepayment of the 2018 SMFH Credit Facility thereby reducing the amount outstanding thereunder to approximately $ 74.7 million as of such date, (ii) the establishment of Tranche A and Tranche B loans under the 2018 SMFH Credit Facility (each as defined the 2018 SMFH Credit Facility) and (iii) the change in the reference rate for Tranche B from LIBOR to SOFR. Tranche A was comprised of approximately $ 19.8 million of the principal amount of the loan and maintained the same Margin (as defined in the 2018 SMFH Credit Facility) over LIBOR of 4.75 % per annum through December 31, 2022, thereafter reverting to 3.75 % per annum and the same maturity date of September 30, 2023 . Tranche B was comprised of approximately $ 54.9 million of the principal amount of the loan, permanently maintained the Margin over SOFR (previously LIBOR) at 4.75 % per annum and extended the maturity date from September 30, 2023 to March 31, 2026 . Proceeds from the 2023 SMFH Credit Facility were used to satisfy in full the 2018 SMFH Credit Facility. Sea-Cat Crewzer III Term Loan Facility. On April 21, 2016, Sea-Cat Crewzer III LLC, a wholly owned subsidiary of the Company (“Sea-Cat Crewzer III”) entered into a € 27.6 million term loan facility (payable in U.S. dollars) secured by the vessels owned by Sea-Cat Crewzer III and fully guaranteed by SEACOR Marine (the “Sea-Cat Crewzer III Loan Facility”). Borrowings under the facility bear interest at a Commercial Interest Reference Rate of 2.76 % per annum. During the years ended December 31, 2017 and 2016, Sea-Cat Crewzer III drew $ 7.1 million and $ 22.8 million, respectively, under the facility and incurred issue costs of $ 2.7 million in 2016 related to this facility. During the year ended December 31, 2018 Sea-Cat Crewzer III made scheduled payments of $ 3.1 million, related to this facility. On December 26, 2019, Sea-Cat Crewzer III, SEACOR Marine, Banco Santander S.A. (as mandated lead arranger and agent), and Santander Bank, N.A. (as lender) entered into Amendment No. 1 to the Sea-Cat Crewzer III Loan Facility, which provided for, among other things, an increase to the maximum debt to capitalization ratio required to be maintained thereunder. On December 24, 2020, Sea-Cat Crewzer III, SEACOR Marine, Banco Santander S.A. (as mandated lead arranger and agent), and Santander Bank, N.A. (as lender) entered into Amendment No. 2 to the Sea-Cat Crewzer III Loan Facility, which provided for, among other things, a waiver of the covenant breaches related to maximum debt to capitalization ratio and the exclusion of certain obligations of the guarantor from the guarantor’s net financial debt for purposes of calculating the guarantor’s permitted net financial debt to equity. The original loan agreement did not expressly exclude certain obligations of the guarantor, including but not limited to non-recourse obligations. On July 3, 2023, Sea-Cat Crewzer III, SEACOR Marine, Banco Santander S.A. (as mandated lead arranger and agent), and Santander Bank, N.A. (as lender) entered into Amendment No. 3 to the Sea-Cat Crewzer III Loan Facility, which provided for an amendment of the substitute reference rate from LIBOR to SOFR. As of December 31, 2023, Sea-Cat Crewzer III was in compliance with all debt covenants and lender requirements. SEACOR Delta Shipyard Financing. Eight PSVs built by COSCO Shipping Heavy Industry (Guangdong) Co., Ltd. (the “COSCO (Guangdong) Shipyard” and such PSVs, the “SEACOR Delta PSVs”) were acquired by vessel owning subsidiaries (“SEACOR Delta SPVs”) of SEACOR Offshore Delta LLC, a wholly owned subsidiary of the Company and formerly known as SEACOSCO Offshore LLC, pursuant to deferred purchase agreements with COSCO (Guangdong) Shipyard (the “SEACOR Delta Shipyard Financing”). The SEACOR Delta Shipyard Financing provides for amortization of the purchase price for each SEACOR Delta PSV over a period of 10 years from delivery bearing a floating annual interest rate of three-month LIBOR plus 4.0 %. SEACOR Offshore Delta LLC has taken delivery of all eight SEACOR Delta PSVs, seven with a 2018 or 2019 year of build, and one with a 2020 year of build. The payment obligations of the SEACOR Delta SPVs under the SEACOR Delta Shipyard Financing for each vessel is secured by a first lien mortgage on the vessel and a pledge of the SEACOR Delta SPV’s equity, and SEACOR Marine provided a limited deficiency guarantee solely with respect to the shortfall in vessel collateral value, if any, in the event the COSCO (Guangdong) Shipyard exercises its remedies under the mortgages. SEACOR Alpine Credit Facility. On June 16, 2023, SEACOR Alps LLC (“SEACOR Alps”), SEACOR Andes LLC (“SEACOR Andes”), and SEACOR Atlas LLC (“SEACOR Atlas” and, together with SEACOR Alps and SEACOR Andes, the “SEACOR Alpine Borrowers”), each a wholly owned subsidiary of the Company, as borrowers, entered into a $ 28.0 million senior secured term loan facility, by and among the SEACOR Alpine Borrowers, SEACOR Marine, as a guarantor, SEACOR Marine Alpine LLC, a wholly owned subsidiary of the Company, and Mountain Supply LLC, an affiliate of Hudson Structured Capital Management, as lender, facility agent and security trustee (the “SEACOR Alpine Credit Facility”). The proceeds of the SEACOR Alpine Credit Facility were made available to the SEACOR Alpine Borrowers in three tranches and were used to satisfy in full amounts outstanding under the SEACOR Alpine Shipyard Financing (as defined below). The funds available under the SEACOR Alpine Credit Facility were fully drawn on June 27, 2023. The SEACOR Alpine Credit Facility matures on June 27, 2028 (the “SEACOR Alpine Maturity Date”). The principal amount of each of the three tranches of the SEACOR Alpine Credit Facility is to be repaid in monthly installments of (i) $ 100,000 for the first eight ( 8 ) installments, (ii) $ 140,000 for the following twenty-four ( 24 ) installments, and (iii) $ 100,000 for each installment thereafter until the SEACOR Alpine Maturity Date. The SEACOR Alpine Credit Facility bears interest at a fixed rate of 10.25 % per annum. The loan may be prepaid at any time in amounts of $ 500,000 or greater, subject to the payment of prepayment interest in respect of the loan or tranche (or portions thereof) being prepaid as follows: (A) if such prepayment is made prior to the first anniversary of the drawdown date, an amount equal to the greater of (x) the amount of unpaid interest which would have accrued until the first anniversary of the drawdown date and (y) 1.5 % of the principal amount of the loan being prepaid, (B) if such prepayment is made on or after the first anniversary of the drawdown date but prior to the third anniversary of the drawdown date, 1.0 % of the principal amount of the loan being prepaid, and (C) if such prepayment is made on or after the third anniversary of the drawdown date, no prepayment interest shall be payable. The SEACOR Alpine Credit Facility contains customary covenants for financings of this type including financial maintenance and restrictive covenants, including the maintenance of certain ratios such as the aggregate collateral vessel value to the sum of the outstanding principal amounts of the loans. The SEACOR Alpine Credit Facility restricts the payment of dividends and distributions and the ability of the SEACOR Alpine Borrowers to make certain investments. In addition, the SEACOR Alpine Credit Facility includes customary events of default. In connection with the SEACOR Alpine Credit Facility, SEACOR Marine issued a guaranty with respect to the obligations of the SEACOR Alpine Borrowers under the SEACOR Alpine Credit Agreement and related documents. This guaranty includes, among other customary covenants, various financial covenants, including minimum liquidity, and debt-to-capitalization and interest coverage ratios. On September 8, 2023, SEACOR Marine entered into an amended and restated guaranty (“A&R SEACOR Alpine Credit Facility Guaranty”) with respect to the SEACOR Alpine Credit Facility. The A&R SEACOR Alpine Credit Facility Guaranty aligns the financial covenants and conditions relating to the payment of dividends and distributions reflected therein with those reflected in the 2023 SMFH Credit Facility Guaranty described above. SEACOR Alpine Shipyard Financing. In 2019, the Company committed to take possession of three Rolls Royce UT 771 CDL designed diesel electric powered PSVs of 3,800 tons delivered deadweight capacity with dynamic position class 2 and firefighting class 1 notations. As part of this transaction, the shipbuilder, COSCO Shipping Heavy Industry (Zhoushan) Co. Ltd., agreed to finance 70 % of the cost of each of these vessels pursuant to a deferred payment agreement (the “SEACOR Alpine Shipyard Financing”). The SEACOR Alpine Shipyard Financing called for increasing quarterly payments of principal and interest payments that bear interest at a fixed annual rate of 5 % over a four-year term from delivery. The payment obligations were secured by a first priority mortgage on the three vessels acquired. The Company took delivery of the three vessels, namely the SEACOR Alps, the SEACOR Andes and the SEACOR Atlas on September 30, 2019, April 20, 2020 and August 10, 2020, respectively. Proceeds from the SEACOR Alpine Credit Facility were used to satisfy in full the SEACOR Alpine Shipyard Financing. SEACOSCO Acquisition Debt. On June 30, 2020, the Company completed the acquisition of the 50 % membership interest in SEACOR Offshore Delta LLC, formerly known as SEACOSCO Offshore LLC (such remaining interests, the “SEACOSCO Interests”) that it did not already own. SEACOR Offshore Delta LLC is the owner of the eight SEACOR Delta PSVs. The price payable by the Company for the SEACOSCO Interests was $ 28.2 million (the “SEACOSCO Purchase Price”), $ 8.4 million of which was paid to the sellers (the “SEACOSCO Sellers”) at the closing. The deferred portion of the SEACOSCO Purchase Price was payable in annual installment payments of $ 1.0 million, $ 2.5 million and $ 2.5 million in the first, second and third year after the signing date of the acquisition, respectively, with the remaining $ 13.7 million due four years after such date (such deferred portion of the SEACOSCO Purchase Price, “SEACOSCO Acquisition Debt”). The SEACOSCO Acquisition Debt accrued interest at a fixed annual rate of 1.5 %, 7.0 %, 7.5 % and 8.0 % for the first through fourth years after the signing date, respectively. Proceeds from the 2023 SMFH Credit Facility were used to satisfy in full the SEACOSCO Acquisition Debt. SEACOR 88/888 Term Loan Facility. On July 5, 2018, SEACOR 88 LLC and SEACOR 888 LLC, each a wholly owned subsidiary of the Company, entered into a certain $ 11.0 million senior secured loan agreement with DNB Bank ASA, New York Branch and DNB Capital LLC (as amended, the “SEACOR 88/888 Term Loan”), and used the funds to acquire two AHTS vessels, the SEACOR 88 and SEACOR 888, that were previously managed (but not owned) by the Company. The SEACOR 88/888 Term Loan was secured by the SEACOR 88 and SEACOR 888 vessels, and SEACOR Marine provided a limited guaranty of such loan under which claims recoverable from SEACOR Marine shall not exceed the lesser of (x) $ 5.5 million and (y) 50 % of the obligations outstanding at the time a claim is made thereunder. The SEACOR 88/888 Term Loan was amended on August 2, 2022 to provide for, among other things, (i) the extension of the maturity date of the SEACOR 88/888 Term Loan from June 29, 2023 to July 1, 2024, (ii) the change in the reference rate from LIBOR to SOFR and (iii) the amendment of the applicable annual interest rate margin over SOFR (previously LIBOR) from 3.75 % to 4.75 %. Proceeds from the 2023 SMFH Credit Facility were used to satisfy in full the SEACOR 88/888 Term Loan. Tarahumara Shipyard Financing. On July 9, 2021, SMLLC took delivery of the vessel named SEACOR Tarahumara, a 2021 built PSV. Effective upon such delivery and as partial consideration for the acquisition of the vessel, SMLLC entered into a loan agreement with Master Boat Builders, Inc. with respect to a term loan in the amount of $ 6.5 million. This term loan matures in 2025 with interest-only payments for the first year, with the loan fully amortizing on a straight-line basis over the remaining term. The term loan bears interest at a fixed annual rate of 6 % and is secured by a first lien mortgage on the vessel. SMLLC is the sole borrower under the loan agreement (the “Tarahumara Shipyard Financing”). Proceeds from the 2023 SMFH Credit Facility were used to satisfy in full the Tarahumara Shipyard Financing, at a 7 % discount to book value. SEACOR Offshore OSV. In connection with the OSV Partners Merger, completed on December 31, 2021, SEACOR Marine and SEACOR Offshore OSV assumed and guaranteed approximately $ 18.1 million of OSV Partners I’s third-party indebtedness outstanding under that certain second amended and restated credit facility agreement with DNB Capital LLC and Comerica Bank, as lenders, and administered by DNB Bank ASA, New York Branch, dated as of December 31, 2021 (as amended from time to time, the “SEACOR OSV Credit Facility”). The Company’s payment obligations under the SEACOR OSV Credit Facility were secured by a first lien mortgage on the five acquired vessels. On December 22, 2022, the SEACOR OSV Credit Facility was amended to provide for, among other things, the division of the loans under the SEACOR OSV Credit Facility into two tranches of debt, Class A Debt (as defined in the SEACOR OSV Credit Facility) deemed loaned under the SEACOR OSV Credit Facility by DNB Capital LLC in an amount of approximately $ 10.9 million as of the date of the amendment, and Class B Debt (as defined in the SEACOR OSV Credit Facility) deemed loaned under the SEACOR OSV Credit Facility by Comerica Bank in an amount of approximately $ 5.6 million as of the date of the amendment. In addition, (a) the Final Payment Date (as defined in the SEACOR OSV Credit Facility) of the Class A Debt was extended from December 31, 2023 to March 31, 2026 , (b) the Margin (as defined in the SEACOR OSV Credit Facility) of the Class A Debt was increased from 4.68 % per annum to 4.75 % per annum, and (c) the amortization profile of the SEACOR OSV Credit Facility was amended such that the borrowers thereunder are required to pay $ 500,000 per quarter up to and including the quarter ending on December 31, 2023 (at which point all amounts outstanding under the Class B Debt shall become due and payable), and $ 330,450 per quarter thereafter up to and including March 31, 2026 . The Class B Debt maintained substantially the same terms and conditions under the SEACOR OSV Credit Facility as it had prior to Amendment No. 8. Proceeds from the 2023 SMFH Credit Facility were used to satisfy in full the SEACOR OSV Credit Facility. Falcon Global. On June 10, 2021, SEACOR Marine, Falcon Global USA LLC, a wholly owned subsidiary of the Company (“FGUSA”), and certain subsidiaries of FGUSA, entered into a Second Amendment and Conditional Payoff Agreement (the “Conditional Payoff Agreement”) in respect of that certain (i) term and revolving loan facility, dated as of February 8, 2018, administered by JPMorgan Chase Bank, N.A. (as amended, the “FGUSA Credit Facility”) and (ii) obligation guaranty issued by SEACOR Marine, dated February 8, 2018, pursuant to which SEACOR Marine provided a guarantee of certain limited obligations of FGUSA under the FGUSA Credit Facility (as amended, the “FGUSA Obligation Guaranty”). Under the terms of the Conditional Payoff Agreement, the $ 117.3 million of principal outstanding under the FGUSA Credit Facility was deemed satisfied

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	7. INCOME TAXES (Loss) Income before income tax expense (benefit) and equity in earnings (losses) of 50 % or less owned companies derived from U.S. and foreign companies for the years ended December 31 were as follows (in thousands): 2023 2022 2021 United States $ ( 3,576 ) $ ( 48,037 ) $ 34,955 Foreign ( 335 ) ( 21,881 ) ( 29,425 ) Eliminations ( 160 ) ( 160 ) 1,097 $ ( 4,071 ) $ ( 70,078 ) $ 6,627 The components of income tax expense (benefit) for the years ended December 31 were as follows (in thousands): 2023 2022 2021 Current: Federal $ ( 18 ) $ 90 $ — State 47 ( 78 ) 271 Foreign 13,831 8,473 6,362 13,860 8,485 6,633 Deferred: Federal ( 5,062 ) 7 4,892 State 8 90 ( 32 ) Foreign ( 7 ) — — ( 5,061 ) 97 4,860 $ 8,799 $ 8,582 $ 11,493 The following table reconciles the difference between the statutory federal income tax rate for the Company and the effective income tax rate for the years ended December 31: 2023 2022 2021 Statutory rate ( 21.0 )% ( 21.0 )% 21.0 % Income (loss) of foreign subsidiaries not includable in U.S. return and foreign withholding tax 223.4 % 20.8 % 141.6 % Non-Deductible Expenses 1.2 % 0.3 % 0.4 % JV equity earnings — % — % 3.8 % Sale of investments in 50 % or less owned companies — % 11.1 % — % 162(m) - Executive compensation 17.8 % — % — % Return to provision — % — % 0.4 % State Taxes 1.1 % — % 2.7 % Subpart F Income 6.6 % 0.7 % 2.0 % Share Award Plans ( 12.9 )% 0.3 % 1.5 % Other — 0.1 % — % Effective Tax Rate 216.2 % 12.3 % 173.4 % For the year ending December 31, 2023 , the Company’s effective income tax rate of 216.2 % was primarily due to foreign withholding taxes. For the year ending December 31, 2022, the Company’s effective income tax rate of 12.3 % was primarily due to foreign taxes paid that are not creditable against U.S. income taxes, foreign losses for which there is no benefit in the U.S. and the sale of investments in 50 % or less owned companies. For the year ending December 31, 2021, the Company’s effective income tax rate of 173.4 % was primarily due to foreign taxes not creditable against U.S. income taxes and foreign subsidiaries with current losses for which there is no current or future federal income tax benefit. The components of net deferred income tax liabilities as of December 31 were as follows (in thousands): 2023 2022 Deferred tax liabilities: Property and equipment $ 48,779 $ 56,618 Other 3,533 6,094 Total deferred tax liabilities 52,312 62,712 Deferred tax assets: Federal Net Operating Loss Carryforwards 10,887 14,822 Other 10,632 9,619 21,519 24,441 Valuation Allowance ( 4,925 ) ( 2,508 ) Total deferred tax assets 16,594 21,933 Net deferred tax liabilities $ 35,718 $ 40,779 The Section 163(j) interest deduction limitations were amended to limit the ability of the Company to deduct net interest expense to 30 % of adjusted taxable income. For the year ended December 31, 2023, $ 1.8 million of previously suspended interest was deductible and there is no remaining carry forward. Net operating losses generated in 2017 and prior may be carried forward 20 years (expiring in 2037 ). Future utilization of net operating losses (“NOL”) arising in tax years after December 31, 2017 are limited to 80 % of taxable income and are allowed to be carried forward indefinitely. As of December 31, 2023, the Company has utilized all of its remaining net operating losses generated prior to December 31, 2017, and has $5 1.8 million of net operating losses generated after 2017. As of December 31, 2023 , the Company's valuation allowance of $ 4.9 million related primarily to foreign tax credit carryforwards which the Company expects to expire unutilized and Louisiana state net operating loss carryforwards.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Strategies	12 Months Ended
	Dec. 31, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Strategies	8. DERIVATIVE INSTRUMENTS AND HEDGING STRATEGIES Derivative instruments are classified as either assets, which are included in other receivables in the accompanying consolidated balance sheets, or liabilities based on their individual fair values. The fair values of the Company’s derivative instruments as of December 31 were as follows (in thousands): 2023 2022 Derivative Derivative Derivative Derivative Derivatives designated as hedging instruments: Interest rate swap agreements (cash flow hedges) $ — $ — $ 526 $ — Derivatives not designated as hedging instruments: Forward Exchange Contract $ 608 $ — $ — $ — Economic Hedges. The Company may enter and settle forward currency exchange, option and future contracts with respect to various foreign currencies. These contracts enable the Company to buy currencies in the future at fixed exchange rates, which could offset possible consequences of changes in currency exchange rates with respect to the Company’s business conducted outside of the U.S. The Company generally does not enter into contracts with forward settlement dates beyond 12 to 18 months. During the fourth quarter of 2023, the Company entered into a forward exchange contract related to the purchase of hybrid battery power systems. During the years ended December 31, 2023 and December 31, 2021, the Company recognized gains of $ 0.6 million and $ 0.4 million, respectively, on these contracts which were recognized concurrently in earnings. As of December 31, 2022, the Company had no open forward currency exchange contracts. Cash Flow Hedges. The Company may from time to time enter into interest rate swap agreements designated as cash flow hedges. By entering into interest rate swap agreements, the Company can convert the variable interest component of certain of their outstanding borrowings to a fixed interest rate. The Company recognized losses on derivative instruments designated as cash flow hedges of $ 0.5 million for the year ended December 31, 2023 and gains of $ 2.3 million for the years ended December 31, 2022 and 2021 as a component of other comprehensive income (loss). As of December 31, 2023, there were no interest rate swaps held by the Company. Derivative Instruments. The Company utilizes derivative instruments to manage the volatility of cash flows due to fluctuating interest rates. All derivative instruments not qualifying for the normal purchase and normal sale exception are recorded on the balance sheets at fair value. The treatment of the periodic changes in fair value will depend on whether the derivative is designated and effective as a hedge for accounting purposes. If a derivative qualifies for hedge accounting and is designated as a cash flow hedge, the effective portion of the change in fair value of the derivative is deferred in Accumulated Other Comprehensive Income (“AOCI”), a component of owners’ equity, and reclassified to earnings when the forecasted transaction occurs. Cash flows from a derivative instrument designated as a hedge are classified in the same category as the cash flows from the item being hedged. As such, we include the cash flows from interest rate derivative instruments in interest expense. If a derivative does not qualify as a hedge or is not designated as a hedge, the gain or loss resulting from the change in fair value on the derivative is recognized currently in earnings as a component of other income (expense). We formally document all relationships between hedging instruments and hedged items, as well as its risk management objectives and strategy for undertaking the hedge. This documentation includes the specific identification of the hedging instrument and the hedged item, the nature of the risk being hedged and the manner in which the hedging instrument’s effectiveness will be assessed. At the inception of the hedge, and on an ongoing basis, we assess whether the derivatives used in hedging transactions are highly effective in offsetting changes in cash flows of hedged items. The relationship between the hedging instrument and the hedged item must be highly effective in achieving the offset of changes in cash flows attributable to the hedged risk both at the inception of the contract and on an ongoing basis. We measure hedge ineffectiveness on a quarterly basis and reclassify any ineffective portion of the gain or loss related to the change in fair value to earnings in the current period. We will discontinue hedge accounting on a prospective basis when a hedge instrument is terminated or ceases to be highly effective. Gains and losses deferred in AOCI related to cash flow hedges for which hedge accounting has been discontinued remain deferred until the forecasted transaction occurs. If it is no longer probable that a hedged forecasted transaction will occur, deferred gains or losses on the hedging instrument are reclassified to earnings immediately. For balance sheet classification purposes, we analyze the fair values of the derivative instruments on a contract-by-contract basis and report the related fair values and any related collateral by counterparty on a gross basis. Realized and unrealized gains and losses on derivatives designated as cash flow hedges that are entered into by the Company’s 50% or less owned companies are also reported as a component of the Company’s other comprehensive loss in proportion to the Company’s ownership percentage, with reclassifications and ineffective portions being included in equity in earnings (losses) of 50% or less owned companies, net of tax, in the accompanying consolidated statements of income (loss). The fair value of our derivative instruments, depending on the type of instrument, is determined by the use of present value methods or standard option valuation models with assumptions about commodity prices based on those observed in underlying markets. The estimated fair value is net of an adjustment for credit risk based on the default probabilities by year as indicated by market quotes for the counterparties’ credit default swap rates. The following tables reflect amounts recorded in Other Comprehensive Income (Loss) (“OCI”) and amounts reclassified from OCI to revenue and expense for the periods indicated: Gains (Losses) Recognized in OCI on Derivatives Derivatives in Cash Flow Hedging Relationships 2023 2022 2021 Interest rate swap contracts $ 56 $ 1,608 $ 219 Joint venture interest rate swap contracts — 941 ( 588 ) (Gains) Losses Reclassified from OCI into Income Location of (Gains) Losses 2023 2022 2021 Interest expense $ ( 571 ) $ 694 $ 1,648 Our consolidated earnings are also affected by the use of the mark-to-market method of accounting for derivative instruments that do not qualify for hedge accounting or that have not been designated as hedges. The changes in fair value of these instruments are recorded on the balance sheet and through earnings rather than being deferred until the anticipated transaction settles. The use of mark-to-market accounting for financial instruments can cause non-cash earnings volatility due to changes in the underlying commodity price indices. Other Derivative Instruments. The Company recognized gains on derivative instruments not designated as hedging instruments for the years ended December 31 as follows (in thousands): Derivative gains (losses), net 2023 2022 2021 Conversion option liability on Old Convertible Notes $ — $ — $ 2 Forward currency exchange, option and future contracts 608 — 390 $ 608 $ — $ 392 The conversion option liability related to the bifurcated embedded conversion option in the Old Convertible Notes, issued to investment funds managed and controlled by Carlyle, was exchanged for the New Convertible Notes (see “Note 6. Long-Term Debt”). The forward currency exchange contract in 2023 relates to the purchase of hybrid battery power systems. The forward currency exchange contract in 2021 relates to £ 31.5 million swap related to the proceeds received from the sale of Windcat Workboats (see “Note 3. Equipment Acquisitions and Dispositions”).

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	9. FAIR VALUE MEASUREMENTS The fair value of an asset or liability is the price that would be received to sell an asset or transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company utilizes a fair value hierarchy that maximizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value and defines three levels of inputs that may be used to measure fair value. Level 1 inputs are quoted prices in active markets for identical assets or liabilities. Level 2 inputs are observable inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly, including quoted prices for similar assets or liabilities in active markets, quoted prices in markets that are not active, inputs other than quoted prices that are observable for the asset or liability, or inputs derived from observable market data. Level 3 inputs are unobservable inputs that are supported by little or no market activity and are significant to the fair value of the assets or liabilities. The Company’s financial assets and liabilities as of December 31 that are measured at fair value on a recurring basis were as follows (in thousands): Level 1 Level 2 Level 3 2023 ASSETS Derivative instruments $ — $ 608 $ — 2022 LIABILITIES Derivative instruments $ — $ 526 $ — The estimated fair values of the Company’s other financial assets and liabilities as of December 31 were as follows (in thousands): Estimated Fair Value Carrying Level 1 Level 2 Level 3 2023 ASSETS Cash, cash equivalents and restricted cash $ 84,131 $ 84,131 $ — $ — LIABILITIES Long-term debt, including current portion 315,909 — 307,653 — 2022 ASSETS Cash, cash equivalents and restricted cash $ 43,045 $ 43,045 $ — $ — LIABILITIES Long-term debt, including current portion 321,631 — 314,979 — The carrying value of cash, cash equivalents and restricted cash approximates fair value. The fair value of the Company’s long-term debt was estimated based upon quoted market prices or by using discounted cash flow analysis based on estimated current rates for similar types of arrangements. Considerable judgment was required in developing certain of the estimates of fair value and, accordingly, the estimates presented herein are not necessarily indicative of the amounts that the Company could realize in a current market exchange. Property and equipment. During the year ended December 31, 2023 , the Company recognized impairment charges of $ 0.7 million for one leased-in AHTS to adjust for indicative cash flows and the cost to return the vessel to its owner. During the year ended December 31, 2022, the Company recognized impairment charges totaling $ 2.9 million. The Company recorded impairment charges of $ 0.9 million for one FSV classified as held for sale and sold during 2022. In addition, the Company recorded impairment charges of $ 0.7 million for one leased-in AHTS as it is not expected to return to active service during its remaining lease term. Additionally, the Company recorded impairment charges of $ 1.3 million for other equipment and classified such equipment as assets held for sale as the Company expects to sell the equipment within one year. The impairment charges for the assets held for sale are included in (losses) gains on asset dispositions and impairments in the accompanying consolidated statements of income (loss). Investments, at equity, in 50% or less owned companies. During the year ended December 31, 2021, the Company received a distribution from one of its investments in 50% or less owned companies, MEXMAR Offshore, in the amount of $ 12.0 million of which $ 9.4 million was in excess of the Company’s investment balance of $ 2.6 million. The beginning balance of the Company’s investment in MEXMAR Offshore was zero . The Company did not make any further adjustments to any of its investments in 50% or less owned companies.

Warrants

Warrants	12 Months Ended
	Dec. 31, 2023
Warrants and Rights Note Disclosure [Abstract]
Warrants	10. WARRANTS In connection with various transactions, the Company issued an aggregate of 2,560,456 warrants to purchase shares of Common Stock at an exercise price of $ 0.01 per share (“Warrants”). As of December 31, 2023, 1,304,333 Warrants remain outstanding, which are comprised entirely of warrants issued to and held by the Carlyle Investors. On November 9, 2023, 17,635 Warrants were exercised for a penny per share. In connection with the exercise of Warrants on November 9, 2023, 16 shares of Common Stock were withheld as payment for the exercise price of the exercised Warrants. On January 17, 2023, 117,515 Warrants were exercised. In connection with the exercise of Warrants on January 17, 2023, 121 shares of Common Stock were withheld as payment for the exercise price of the exercised Warrants. On December 23, 2021, 48,809 Warrants were exercised for a penny per share, resulting in 1,439,483 Warrants outstanding as of December 31, 2021. In connection with the exercise of Warrants on December 23, 2021, 149 shares of Common Stock were withheld as payment for the exercise price of the exercised Warrants.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Stockholders' Equity	11. STOCKHOLDERS' EQUITY On January 17, 2023, 117,515 Warrants were exercised, which, together with the Warrant exercise on November 9, 2023, resulted in 1,304,333 Warrants outstanding as of December 31, 2023, which are comprised entirely of warrants issued to the Carlyle Investors. In connection with the exercise of Warrants on January 17, 2023, 121 shares of Common Stock were withheld as payment for the exercise price of the exercised Warrants. On November 9, 2023, 17,635 Warrants were exercised for a penny per share, which are comprised entirely of warrants issued to the Carlyle Investors. In connection with the exercise of Warrants on November 9, 2023, 16 shares of Common Stock were withheld as payment for the exercise price of the exercised Warrants. On November 1, 2023, SEACOR Marine entered into an at-the-market sales agreement (the “Sales Agreement”) with B. Riley Securities, Inc. (the “Sales Agent”), relating to the issuance and sale from time to time by SEACOR Marine (the “ATM Program”), as principal or through the Sales Agent, of shares of Common Stock having an aggregate gross sales price of up to $ 25.0 million (the “ATM Shares”). Sales of the ATM Shares, if any, under the Sales Agreement may be made in ordinary brokers’ transactions, to or through a market maker, on or through the New York Stock Exchange (the “NYSE”), the existing trading market for the Common Stock, or any other market venue where the Common Stock may be traded, in the over-the-counter market, in privately negotiated transactions, or through a combination of any such methods of sale. The Sales Agent may also sell the ATM Shares by any other method permitted by law. During the fourth quarter of 2023, the Company issued and sold 7,674 shares of Common Stock in the ATM Program at an average price of $ 13.1891 per share, with net proceeds to the Company of $ 23,590 , net of costs directly attributable to such issuance and sale of $ 77,623 . No other shares of Common Stock were sold in 2023 under the ATM Program. On December 31, 2021, pursuant to the OSV Partners Merger Agreement OSV Partners I merged with and into SEACOR Offshore OSV, with SEACOR Offshore OSV surviving the OSV Partners Merger. In connection with the consummation of the OSV Partners Merger, the Company issued an aggregate number of 1,567,935 shares of Common Stock, as follows: (i) 531,872 shares of Common Stock as consideration for the OSV Partners Merger paid to OSV Partners I’s limited partners (other than the Company and its subsidiaries), and (ii) 1,036,063 shares of Common Stock as payment to settle all amounts and other obligations outstanding under that certain Subordinated PIK Loan Agreement and paid to the former lenders thereunder (all of whom were limited partners of OSV Partners I). On December 23, 2021, 48,809 Warrants were exercised for a penny per share, resulting in 1,439,483 Warrants outstanding as of December 31, 2021. In connection with the exercise of Warrants on December 23, 2021, 149 shares of Common Stock were withheld as payment for the exercise price of the exercised Warrants.

Noncontrolling Interests in Sub

Noncontrolling Interests in Subsidiaries	12 Months Ended
	Dec. 31, 2023
Noncontrolling Interest [Abstract]
Noncontrolling Interests in Subsidiaries	12. NONCONTROLLING INTERESTS IN SUBSIDIARIES Noncontrolling interests in the Company’s consolidated subsidiaries as of December 31 were as follows (in thousands): Noncontrolling 2023 2022 VEESEA Holdings Inc. 1.8 % $ 321 $ 321

Savings and Multi-employer Pens

Savings and Multi-employer Pension Plans	12 Months Ended
	Dec. 31, 2023
Retirement Benefits [Abstract]
Savings and Multi-employer Pension Plans	13. SAVINGS AND MULTI-EMPLOYER PENSION PLANS SEACOR Marine Savings Plan. On January 1, 2016, the Company’s eligible U.S. based employees were transferred from the SEACOR Holdings sponsored defined contribution plan to the “SEACOR Marine 401(k) Plan,” a new Company sponsored defined contribution plan (the “Savings Plan”). Effective upon the June 1, 2017 spin-off from SEACOR Holdings, the Company discontinued its contribution to the Savings Plan up until January 1, 2019, at which time the Company’s contribution were limited to 1 % of an employee’s wages. In 2020, the Company increased its matching contributions to 2 % of an employee’s wages. Effective January 1, 2022, the Company increased its matching contributions to 3 % of an employee’s wages and effective July 1, 2022 the Company increased such contribution to 4 %. The Savings Plan costs for the years ended December 31, 2023, 2022 and 2021 were $ 1.1 million, $ 0.8 million and $ 0.2 million, respectively. MNOPF and MNRPF. Certain of the Company’s subsidiaries are participating employers in two industry-wide, multi-employer, defined benefit pension funds in the United Kingdom (“U.K.”): the U.K Merchant Navy Officers Pension Fund (“MNOPF”) and the U.K. Merchant Navy Ratings Pension Fund (“MNRPF”). The Company’s participation in the MNOPF began with the acquisition of the Stirling group of companies (the “Stirling Group”) in 2001 and relates to certain officers employed between 1978 and 2002 by the Stirling Group and/or its predecessors. The Company’s participation in the MNRPF also began with the acquisition of the Stirling Group in 2001 and relates to ratings employed by the Stirling Group and/or its predecessors through today. Both of these plans are in deficit positions and, depending upon the results of future actuarial valuations, it is possible that the plans could experience funding deficits that will require the Company to recognize payroll related operating expenses in the periods invoices are received. As of December 31, 2023, all invoices received related to MNOPF and MNRPF have been settled in full. On October 19, 2021, the Company was informed by the MNRPF that two issues had been identified during a review of the MNRPF by the applicable trustee that would potentially give rise to material additional liabilities for the MNRPF. On November 23, 2023, the trustee advised that following the tri-annual valuation, $ 1.5 million (£ 1.2 million) of the potential cumulative funding deficit of the MNRPF was allocated to the Company as a participating employer, including the additional liabilities mentioned above. During 2023, the Company recognized payroll related operating expenses of $ 1.5 million (£ 1.2 million) for its allocated share of the potential cumulative funding deficit, which the Company will be invoiced for during 2024 and 2025. Other Plans. Certain employees participate in other defined contribution plans in various international regions. During the years ended December 31, 2023, 2022 and 2021 , the Company incurred costs, primarily from employer matching contributions of $ 0.7 million, $ 0.3 million and $ 0.4 million, respectively.

Share Based Compensation

Share Based Compensation	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Share Based Compensation	14. STOCK BASED COMPENSATION Equity Incentive Plan. During 2017, the Company adopted the SEACOR Marine Holdings Inc. 2017 Equity Incentive Plan (the “2017 Plan”) and at the annual meeting of shareholders held on June 9, 2020, the Company’s shareholders approved the SEACOR Marine Holdings Inc. 2020 Equity Incentive Plan (the “2020 Plan”). At the annual meeting of shareholders held on June 7, 2022 (the “Approval Date”), the Company’s shareholders approved the SEACOR Marine Holdings Inc. 2022 Equity Incentive Plan (the “2022 Plan”), which authorized the issuance of 2,450,000 shares of Common Stock under the 2022 Plan plus 6,005 shares of Common Stock remaining available for issuance under the 2020 Plan as of the Approval Date that will be available for issuance under the 2022 Plan. The types of awards under the 2022 Plan may include stock options, stock appreciation rights, restricted stock and restricted stock units, performance awards and other stock-based awards. As of December 31, 2023 , 1,812,963 shares of Common Stock remained available for issuance under the 2022 Plan. Restricted stock typically vests from one to four years after the date of grant, and stock options to purchase shares of Common Stock typically vest and become exercisable from one to four years after date of grant and expire no later than the tenth anniversary of the date of grant for both employees and directors. Performance restricted stock units (“PRSUs”) typically vest on a cliff-basis after three years , subject to certain stock price performance goals. Pursuant to the applicable award agreements, restricted stock and stock options vest subject to the participant’s continued employment with the Company on the applicable vesting date, subject to accelerated vested upon the executive’s death or qualified retirement or, with respect to restricted stock, upon termination by the Company without “cause” (including for disability). Upon any such termination, PRSUs that have been earned with respect to the stock price performance goal(s) will be settled on the third anniversary of the grant date, without regard to the participants employment with the Company as of such date. For options granted, the fair value is estimated on the date of the grant using the Black-Scholes option pricing model with the following assumptions: (a) no dividend yield; (b) weighted average expected volatility; (c) weighted average discount rate; and (d) expected life. The fair value of restricted stock, earned PRSUs and stock options issued to employees and directors, as applicable, is recognized as compensation expense over the period of service that generally coincides with the vesting period of the award. For all award types, forfeitures are recognized as incurred. Distribution of SEACOR Marine Restricted Stock by SEACOR Holdings. Certain officers and employees of the Company previously received compensation through participation in SEACOR Holdings share award plans. Pursuant to the Employee Matters Agreement with SEACOR Holdings, participating Company personnel vested in all outstanding SEACOR Holdings share awards upon the spin-off in 2017 and received SEACOR Marine restricted stock from the spin-off distribution in connection with outstanding SEACOR Holdings restricted stock held. The Company paid SEACOR Holdings $ 2.7 million upon completion of the spin-off for the distribution of 120,693 shares of SEACOR Marine restricted stock, which was fully amortized as of December 31, 2022. Employee Stock Purchase Plan. During 2017, the Company adopted the SEACOR Marine Holdings Inc. 2017 Employee Stock Purchase Plan (the “Marine ESPP”). The Marine ESPP, if implemented by the Board of Directors, will permit the Company to offer shares of its Common Stock for purchase by eligible employees at a price equal to 85 % of the lesser of (i) the fair market value of a share of its Common Stock on the first day of the offering period or (ii) the fair market value of a share of its Common Stock on the last day of the offering period. There are 300,000 shares of the Company’s Common Stock reserved for issuance under the Marine ESPP during the ten years following its adoption. Share Award Transactions. Transactions in connection with the Company’s Equity Incentive Plans during the years ended December 31 were as follows: 2023 2022 2021 Director Stock Awards Granted 60,938 60,787 189,030 Restricted Stock Activity: Outstanding as of the beginning of year 1,682,193 1,163,090 436,714 Granted 660,307 1,036,605 933,705 Vested ( 685,416 ) ( 514,002 ) ( 202,079 ) Forfeited ( 15,000 ) ( 3,500 ) ( 5,250 ) Outstanding as of the end of year (1) 1,642,084 1,682,193 1,163,090 Stock Option Activity: Outstanding as of the beginning of year 1,026,865 1,061,357 1,120,541 Granted — — — Exercised (2) ( 834 ) ( 34,492 ) — Forfeited (3) — — ( 59,184 ) Outstanding as of the end of year 1,026,031 1,026,865 1,061,357 (1) Excludes 156,620 , 216,172 and 354,964 grants of performance-based stock units as of December 31, 2023, 2022 and 2021 , respectively, that are not considered outstanding until such time that they become probable to vest. (2) The intr insic value of the options exercised was less than $ 0.1 million. (3) Forfeitures in 2021 includes 71,684 options forfeited as of December 31, 2021, netted with an adjustment of 12,500 previously granted. During the year ended December 31, 2023, the Company recognized $ 6.3 million of compensation expense related to stock awards, restricted stock and stock options granted to employees and directors under the 2017 Plan, the 2020 Plan and the 2022 Plan with a recognized tax benefit of $ 7.0 million. As of December 31, 2023, the Company had approximately $ 6.6 million in total unrecognized compensation costs. The weighted average period over which the compensation cost of non-vested awards will be recognized is approximately 0.77 years for restricted stock and there are no unvested stock options. During the year ended December 31, 2022, the Company recognized $ 5.0 million of compensation expense related to stock awards, restricted stock and stock options granted to employees and directors under the 2017 Plan, the 2020 Plan and the 2022 Plan with a recognized tax benefit of $ 3.0 million. As of December 31, 2022, the Company had approximately $ 6.3 million in total unrecognized compensation costs. The weighted average period over which the compensation cost of non-vested awards will be recognized is approximately 1.02 and 0.17 years for restricted stock and stock options, respectively. During the year ended December 31, 2021, the Company recognized $ 5.5 million of compensation expense related to stock awards, restricted stock and stock options granted to employees and directors under the 2017 Plan and the 2020 Plan with a recognized tax benefit of $ 0.2 million. As of December 31, 2021, the Company had approximately $ 4.8 million in total unrecognized compensation costs. The weighted average period over which the compensation cost of non-vested awards will be recognized is approximately 1.01 and 0.42 years for restricted stock and stock options, respectively. The weighted average fair value of restricted stock granted under the 2017 Plan, the 2020 Plan and the 2022 Plan were $ 9.67 , $ 5.92 and $ 5.42 for the year ended December 31, 2023, 2022 and 2021 , respectively. The fair value was based on the closing price of the Company’s stock on the day of the grant. The Company did no t grant any options in the years ended December 31, 2023, 2022 and 2021 . There were 834 and 34,492 stock options exercised in December 31, 2023 and December 31, 2022, respectively, and there were no stock options exercised in 2021. During the year ended December 31, 2023, the number of shares and the weighted average grant price of restricted stock transactions were as follows: Restricted Stock Number of Weighted Average Non-Vested as of December 31, 2022 1,682,193 $ 5.68 Granted 660,307 9.67 Vested ( 685,416 ) 10.12 Forfeited ( 15,000 ) 5.82 Non-Vested as of December 31, 2023 1,642,084 7.53 During the year ended December 31, 2023, the number of shares and the weighted average exercise price on stock option transactions were as follows: Stock Options Number of Weighted Average Outstanding as of December 31, 2022 1,026,865 $ 12.66 Granted — — Exercised ( 834 ) 6.97 Forfeited — — Outstanding as of December 31, 2023 (1) 1,026,031 12.66 Exercisable as of December 31, 2023 (2) 1,026,031 12.66 (1) The weighted average remaining contractual term is 4.8 years and the intrinsic value of the options exercised was $ 1.7 million. (2) The weighted average remaining contractual term is 4.8 years and the intrinsic value of the options exercisable was $ 1.7 million.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2023
Related Party Transactions [Abstract]
Related Party Transactions	15. RELATED PARTY TRANSACTIONS Related Party Transactions Policy. The Company has established a written policy for the review and approval or ratification of transactions with related parties (the “Related Party Transactions Policy”) to assist it in reviewing transactions, arrangements or relationships that exceed the threshold for disclosure established under Item 404(a) of Regulation S-K promulgated by the SEC, in which the Company or any of its subsidiaries is a participant, and any Related Party (as defined in the Related Party Transaction Policy) has or will have a direct or indirect interest (“Related Party Transactions”). The Related Party Transactions Policy supplements the Company’s other conflict of interest policies set forth in the Company’s Corporate Governance Guidelines, its Code of Business Conduct and Ethics and its other internal procedures. Transactions with SEACOR Holdings On June 26, 2020, the Company entered into the Tax Refund Agreement with SEACOR Holdings, the Company’s former parent company. The Tax Refund Agreement enabled the Company to utilize NOL generated in 2018 and 2019 to claim refunds for tax years prior to the Company’s spin-off from SEACOR Holdings in 2017 (at which time the Company was included in SEACOR Holdings consolidated tax returns) that were permitted to be carried back pursuant to the provisions of the CARES Act and for which SEACOR Holdings needed to claim the refund on behalf of the Company. As a result, the Company received an aggregate amount of cash tax refunds of $ 32.3 million (including $ 1.1 million of interest paid by the IRS in respect of refund payment delays due in part to the COVID-19 pandemic), of which $ 12.5 million was received prior to March 31, 2021 and the remaining $ 19.8 million was received in April 2021. SEACOR Holdings will retain certain of the funds to facilitate tax savings realized by SEACOR Holdings of no less than 35 % of the amount of its own 2019 NOL. Additionally, a $ 3.0 million transaction fee was paid to SEACOR Holdings concurrently with the signing of the Tax Refund Agreement as consideration for its cooperation in connection with the filing of the applicable tax refund returns. The Tax Refund Agreement did not restrict the use of approximately $ 23.1 million of the refund and required the remaining approximately $ 8.1 million to be deposited into an account to be used solely to satisfy certain of the Company’s obligations that remained guaranteed by SEACOR Holdings which primarily related to vessel operating leases. Two of these vessel operating leases expired in the fourth quarter of 2020, which reduced the remaining guarantee on the three remaining vessels to $ 7.0 million. The remaining three vessel operating leases that SEACOR Holdings guaranteed expired in 2021 and the Company applied the amount deposited to satisfy these obligations. Transactions regarding OSV Partners OSV Partners. In 2013, OSV Partners I was formed to own and operate offshore support vessels with the Company (then a subsidiary of SEACOR Holdings) holding 30.4 % of the initial limited partner interests (“Initial LP Interests”) and a majority of the general partner interests, and the remaining Initial LP Interests held by unrelated third parties. The Company was also appointed the manager of the vessels owned by OSV Partners I entitled to a market management fee. In December 2014, Charles Fabrikant (a former Non-Executive Chairman of SEACOR Marine), John Gellert (President, Chief Executive Officer and Director of SEACOR Marine), Jesús Llorca (Executive Vice President and Chief Financial Officer of SEACOR Marine) and other individuals (some of who were affiliated with the Company’s former parent, SEACOR Holdings), invested in Caroline International Holdings LLC (“Caroline”) and Caroline International Holdings II LLC (“Caroline II” and together with Caroline, the “Caroline Entities”), two entities managed by Mr. Fabrikant and formed solely for the purposes of investing in OSV Partners I. As of December 31, 2021, the aggregate investments of Messrs. Fabrikant, Gellert and Llorca in the Caroline Entities were $ 0.3 million, $ 0.4 million and $ 0.2 million, respectively. No other current executive officer or member of the Board of Directors invested in or has any interests in the Caroline Entities. The following summarizes the investments made by the Caroline Entities in OSV Partners I: • Initial Investment . In 2014, the Caroline Entities purchased Initial LP Interests from two limited partners of OSV Partners I resulting in Caroline owning $ 1.0 million, or 2.6 %, of the Initial LP Interests, and Caroline II owning $ 0.5 million, or 1.3 %. • 2017 Preferred Interests . In 2017, OSV Partners I raised $ 6.0 million from its limited partners in the form of preferred limited partnership interests (the “2017 Preferred Interests”) resulting in Caroline owning $ 0.2 million, or 3.3 %, of the 2017 Preferred Interests, and Caroline II owning $ 0.1 million, or 1.7 %. • Class A Preferred Interests and Second Lien Debt . In 2018, OSV Partners I raised $ 10.0 million from its limited partners, $ 5.0 million in the form of Class A preferred interests (“Class A Preferred Interests”) and $ 5.0 million in the form of second lien debt under the Subordinated PIK Loan Agreement, resulting in Caroline owning $ 0.1 million, or 2.6 %, of the Class A Preferred Interests and $ 0.1 million, or 2.6 %, of the PIK Loan Debt, and Caroline II owning $ 0.1 million, or 1.3 %, of the Class A Preferred Interests and $ 0.1 million, or 1.3 %, of the PIK Loan Debt. Immediately prior to the closing of the OSV Partners Merger described in “OSV Partners Merger” below, the Company owned 30.4 % of the Initial LP Interests, 38.6 % of the 2017 Preferred Interests, 43.0 % of the Class A Preferred Interests, and 43.0 % of the PIK Loan Debt of OSV Partners. Beginning in January 2019, the Company agreed not to charge OSV Partners I the management fee it was contractually entitled to through December 31, 2021 due to continuing liquidity issues of OSV Partners I. For the years ended December 31, 2018 and 2017, the Company received $ 0.6 million of vessel management fees from OSV Partners I for each year. On October 29, 2021, in exchange for $ 2.2 million, the Company acquired from a third party lender approximately $ 4.1 million of the $ 22.1 million of principal owed under OSV Partner I’s amended and restated senior secured term loan credit facility agreement dated as of September 28, 2018 (the “SEACOR OSV Credit Facility” and such acquisition, the “First Lien Debt Acquisition”). OSV Partners Merger. On December 31, 2021, pursuant to the OSV Partners Merger Agreement OSV Partners I merged with and into SEACOR Offshore OSV with SEACOR Offshore OSV surviving the OSV Partners Merger. In connection with the consummation of the OSV Partners Merger, the Company issued an aggregate of 1,567,935 shares of Common Stock to the limited partners of OSV Partners I as follows: (i) 531,872 shares of Common Stock as consideration for the OSV Partners Merger ( “Merger Consideration” ), 80 % of which was paid in respect of Preferred Interests and Class A Preferred Interests, and 20 % in respect of the Initial LP Interests partners (other than the Company and its subsidiaries); and (ii) 1,036,063 shares of Common Stock as consideration to settle all amounts outstanding under the PIK Loan Agreement ( “PIK Loan Consideration”). In connection with the consummation of the OSV Partners Merger, (i) Caroline received an aggregate number of 73,107 shares of Common Stock and (ii) Caroline II received an aggregate of 36,570 shares of Common Stock. Each of the Caroline Entities distributed to its members the Common Stock received in connection with the consummation of the Merger with Mr. Fabrikant receiving 20,172 shares, or 1.3 % of the aggregate number of shares issued as Merger Consideration and PIK Loan Consideration, Mr. Gellert receiving 22,353 shares, or 1.4 % of the aggregate number of shares issued as Merger Consideration and PIK Loan Consideration, and Mr. Llorca receiving aggregate distributions of 9,174 , or 0.6 % of the aggregate number of shares issued as Merger Consideration and PIK Loan Consideration. In addition, a trust of which Mr. Gellert is one of several beneficiaries received an aggregate number of 26,557 shares of Common Stock. In connection with the OSV Partners Merger, the Company and SEACOR Offshore OSV assumed and guaranteed approximately $ 18.1 million of indebtedness outstanding under the SEACOR OSV Credit Facility. The First Lien Debt Acquisition and the OSV Partners Merger were subject to the oversight and received advance approval of the Audit Committee of the Board of Directors (“Audit Committee”) as related party transactions under the Company’s Related Party Transaction Policy. Mr. Gellert recused himself from deliberations by the Audit Committee and ultimately the Board of Directors with respect to the Merger, and the Board of Directors received a third party fairness opinion with respect thereto. Mr. Llorca was also not involved in the related discussions. Mr. Fabrikant no longer served on the Board of Directors as of June 8, 2021 and therefore had no participation in any of the approval processes for these transactions. Transactions with Carlyle Old Convertible Notes . On October 5, 2022, SEACOR Marine and the Carlyle Investors entered into two agreements pursuant to which SEACOR Marine issued the Carlyle Investors (i) $ 90.0 million in aggregate principal amount of the Guaranteed Notes and (ii) $ 35.0 million aggregate principal amount of the New Convertible Notes in exchange for all $ 125.0 million in aggregate principal amount of SEACOR Marine’s Old Convertible Notes outstanding. Guaranteed Notes. The Guaranteed Notes were issued pursuant to the Exchange Agreement (Guaranteed Notes) among SEACOR Marine, as issuer, FG Robert, as the guarantor, and the Carlyle Investors. Pursuant to the Guaranteed Notes Exchange Agreement, SEACOR Marine has the right to pay (i) in cash at a rate of 8.0 % per annum (“Cash Interest ” ) or (ii) partly in cash and partly in-kind by increasing the principal amount of the Guaranteed Notes or issuing additional Guaranteed Notes at a rate of 9.5 % per annum (“Hybrid Interest ” ) with the cash portion of the Hybrid Interest bearing interest at a rate of 4.25 % per annum and in the in-kind portion of the Hybrid Interest bearing interest at a rate of 5.25 % per annum. The Guaranteed Notes mature on July 1, 2026 . The Guaranteed Notes are guaranteed on a senior unsecured basis by FG Robert, the owner of the LB Robert liftboat. SEACOR Marine may redeem some or all of the Guaranteed Notes at any time in minimum denominations of $ 10.0 million, upon not less than 30 nor more than 60 calendar days’ notice, at a price equal to (a) 101 % of the principal amount of the Guaranteed Notes redeemed, if redeemed prior to October 1, 2024 and (b) 100 % of the principal amount of the Guaranteed Notes redeemed, if redeemed on or after October 1, 2024, in each case plus accrued and unpaid interest, if any, to, but not including, the redemption date, provided, SEACOR Marine may not redeem the Guaranteed Notes if the principal amount of Guaranteed Notes and New Convertible Notes outstanding will be equal to or less than $ 50.0 million in the aggregate, unless SEACOR Marine redeems all of the Guaranteed Notes in whole. The Guaranteed Notes Exchange Agreement contains certain customary covenants that among others, limit the ability of (i) SEACOR Marine and FG Robert to incur indebtedness, (ii) FG Robert to create or incur liens, (iii) SEACOR Marine to create liens on the ownership interest of FG Robert, (iv) FG Robert to sell assets, and (v) SEACOR Marine to sell the ownership interest of FG Robert, as well as customary representations and warranties made by SEACOR Marine, FG Robert and the Carlyle Investors and customary events of default. New Convertible Notes. The New Convertible Notes were issued pursuant to the Exchange Agreement (Convertible Notes) among SEACOR Marine, as issuer, and the Carlyle Investors. The New Convertible Notes bear interest at a rate of 4.25 % per annum payable semi-annually in arrears and mature on July 1, 2026 . The New Convertible Notes are convertible into shares of Common Stock at the option of the holders at a conversion rate of 85.1064 shares per $ 1,000 in principal amount of New Convertible Notes (equivalent to a “Conversion Price” of $ 11.75 ) or into warrants to purchase an equal number of shares of Common Stock at an exercise price of $ 0.01 per share in order to facilitate SEACOR Marine’s compliance with the provisions of the Jones Act. In addition, SEACOR Marine has the right to cause the mandatory conversion of the New Convertible Notes into Common Stock if the daily VWAP of the Common Stock equals or exceeds (A) in the case of New Convertible Notes held by affiliates of Carlyle, 150 % of the Conversion Price and (B) in the case of New Convertible Notes held by any Person other than Carlyle, 115 % of the Conversion Price, in each case for each of the 20 consecutive trading days. If SEACOR Marine undergoes a Company Fundamental Change (as defined in the Convertible Notes Exchange Agreement), the holders of the New Convertible Notes may require SEACOR Marine to purchase for cash all or part of the New Convertible Notes at a price equal to 100 % of the principal amount the New Convertible Notes to be purchased, plus accrued and unpaid interest to the date of purchase. The New Convertible Notes may be redeemed, in whole but not in part and only if certain conditions are met, as more fully described in the Convertible Notes Exchange Agreement, at a price equal to 100 % of the principal amount of the New Convertible Notes to be redeemed, plus accrued and unpaid interest to the date of redemption. Under the Convertible Notes Exchange Agreement, the Carlyle Investors have the ability to nominate one director to the Board of Directors if the Carlyle Investors, solely as a result of their ownership of shares of Common Stock owned by the Investors as of October 5, 2022 and ownership of the New Convertible Notes and warrants (including the shares of common stock of the Company issuable upon conversion or exercise thereof), beneficially own collectively 10 % or more of the outstanding shares of common stock of the Company. The Carlyle Investors have not exercised this right. Ms. Anna Mire has been designated by the Carlyle Investors to observe meetings of the Board of Directors pursuant to the Carlyle Investors’ observer rights under the Convertible Notes Exchange Agreement and the Guaranteed Notes Exchange Agreement. This observation right will terminate at the time the Carlyle Investors own less than $ 50.0 million in aggregate principal amount of the New Convertible Notes and Guaranteed Notes or a combination of the New Convertible Notes and our Common Stock representing less than 5.0 % of the Company’s Common Stock outstanding on a fully diluted basis, assuming the conversion of all of the New Convertible Notes and warrants to purchase Common Stock held by the Carlyle Investors. The Convertible Notes Exchange Agreement contains customary representations and warranties made by SEACOR Marine and the Carlyle Investors and contains customary events of default and covenants. The Convertible Notes Exchange Agreement and the transactions contemplated thereby were subject to the oversight of, and received advance approval from, the Audit Committee. During 2023 and 2021, the Carlyle Investors exercised 135,150 and 48,809 warrants, respectively. During 2022, the Carlyle Investors did no t exercise any warrants. As of December 31, 2023, the Carlyle Investors had 1,304,333 outstanding warrants. Transactions with CME Mr. Alfredo Miguel Bejos, a member of the Board of Directors, currently serves as President and Chief Executive Officer of CME. In accordance with the Related Transaction Policy, the Audit Committee has adopted guidelines for addressing ongoing CME-related transactions. On December 20, 2018, MEXMAR Offshore, a joint venture that was 49.0 % owned by a subsidiary of the Company and 51.0 % owned by a subsidiary of CME, acquired UP Offshore. UP Offshore was acquired for nominal consideration. In connection with the acquisition, UP Offshore’s existing debt was refinanced with $ 95.0 million of new indebtedness composed of (i) a $ 70.0 million six-year debt facility provided by UP Offshore’s existing lenders that is non-recourse to the Company, CME or any of their respective subsidiaries, (ii) a $ 15.0 million loan from MexMar, a joint venture between CME and the Company, to fund capital expenditures on two vessels and (iii) a $ 10.0 million loan from MEXMAR Offshore to fund working capital requirements funded by an approximate $ 5.0 million capital contribution to MEXMAR Offshore by each of the Company and CME. Due to losses from equity earnings, the Company’s investment in MEXMAR Offshore was written down to $ 0 in 2019. In July 2020, MEXMAR Offshore purchased from a consortium of banks in Brazil, $ 70.0 million of UP Offshore’s debt for $ 5.5 million, of which the Company’s commitment was $ 2.7 million to fund this purchase. As of December 31, 2020, the Company had loaned its proportional share of this commitment to MEXMAR Offshore of $ 1.96 million. The Company funded its remaining commitment in February 2021. On June 1, 2021, MEXMAR Offshore completed the sale of eight vessels and certain Brazilian entities to OceanPact Serviços Marítimos S.A. and its subsidiary, OceanPact Netherlands B.V., for a total purchase price of $ 30.2 million (the “UP Offshore Sale Transaction”), which resulted in an equity earnings gain from 50 % or less owned companies of $ 2.6 million. On July 23, 2021, the Company received a distribution from MEXMAR Offshore in the amount of $ 12.0 million of which $ 9.4 million was in excess of the Company’s investment balance of $ 2.6 million. The excess was recorded by the Company as a gain from return of investments in 50 % or less owned companies. After giving effect to the UP Offshore Sale Transaction, MEXMAR Offshore, indirectly through certain subsidiaries of UP Offshore, retained ownership of three vessels. As part of the winddown of the MEXMAR Offshore joint venture, ownership of two of these vessels was transferred from subsidiaries of UP Offshore to OVH on October 26, 2021, and the remaining vessel was transferred from a subsidiary of UP Offshore to OVH on November 2, 2021. Upon completion of these transactions, MEXMAR Offshore no longer held income producing assets and as a result, on December 9, 2021, the Company transferred its 49 % interest in MEXMAR Offshore to a subsidiary of CME for nominal consideration and a transaction fee of $ 0.2 million. As of December 31, 2021, the Company does not have any ownership interest in MEXMAR Offshore. Prior to the consummation of the Framework Agreement Transactions described below, the Company also participated in a variety of other joint ventures with CME, including MexMar, SEACOR Marlin LLC and OVH. The joint venture agreements for each of these joint ventures were negotiated at arms-length in the ordinary course of business. MexMar is a joint venture company that was 49 % owned by a wholly owned subsidiary of the Company and 51 % owned by subsidiaries of CME. SEACOR Marlin LLC was a joint venture company that was 49 % owned by a wholly owned subsidiary of the Company and 51 % owned by a wholly owned subsidiary of MexMar. During the year ended December 31, 2021, there was a distribution to the Company from SEACOR Marlin LLC of $ 2.5 million. OVH is a joint venture company that is 49 % owned by a wholly owned subsidiary of the Company and 51 % owned by a subsidiary of CME. On December 10, 2021, OVH and OPEM settled the $ 10.0 million loan in exchange for OPEM making an early repayment of $ 10.5 million, reflecting repayment of the principal amount in full and a prepayment discount and forgiveness of approximately $ 4.1 million of accrued interest. On September 29, 2022, SEACOR Marine and certain of its subsidiaries, on the one hand, and OTM, CME Ireland, and OVH, on the other hand, entered into the Framework Agreement. OTM and CME Ireland are affiliates of CME. Prior to the closing of the Framework Agreement Transactions, the Company owned 49 % of each of MexMar and OVH through SEACOR Marine International, a wholly owned subsidiary of the Company, and the remaining 51 % ownership interests were held by OTM. The Company also owned a minority interest in SEACOR Marlin LLC, the owner of the PSV SEACOR Marlin, and the remaining ownership interests of SEACOR Marlin LLC were held by MexMar. The Framework Agreement provided for, among other things, (i) the sale by the Company of all of the outstanding equity interests of SEACOR Marine International to OTM for a purchase price of $ 66.0 million, (ii) the sale by the Company of the AHTS SEACOR Davis to CME Ireland in exchange for the remaining equity interests in SEACOR Marlin LLC, such that SEACOR Marlin LLC would become a wholly owned subsidiary of the Company, (iii) the transfer of a hybrid battery power system from OVH to the Company as repayment in full of a certain vessel loan agreement by the Company to its former joint venture, and (iv) entry into a bareboat charter agreement between SEACOR Marlin LLC and MexMar. Each of the Framework Agreement Transactions was consummated on September 29, 2022. As a result of the Framework Agreement Transactions, the Company no longer owns any equity interest in either of MexMar or OVH, and the Company owns all of the equity interests in SEACOR Marlin LLC, which owns the PSV SEACOR Marlin. In connection with the closing of the Framework Agreement Transactions, on September 29, 2022, SEACOR Marine Capital, a wholly owned subsidiary of SEACOR Marine, purchased all of the outstanding loans under the Second Amended and Restated Term Loan Credit Facility Agreement, made as of July 8, 2022, by and among MexMar, as the borrower, DNB Capital LLC and The Governor and Company of the Bank of Ireland, each as lenders, and DNB Bank ASA, New York Branch, as facility agent (as amended from time to time, the “MexMar Original Facility Agreement”) for an aggregate amount of $ 28.8 million, representing par value of the loan. The purchase was funded using proceeds received from the Framework Agreement Transactions. On the same date the facility was amended pursuant to a Third Amended and Restated Facility Agreement (“MexMar Third A&R Facility Agreement”) to, among other things, (i) provide for the prepayment by MexMar of approximately $ 8.8 million of the outstanding loan amount, to reduce the outstanding principal on the loan to $ 20.0 million, (ii) modify the definition of “Change of Control”, (iii) modify the maturity date from January 23, 2025 to September 30, 2023 , (iv) decrease the minimum cash requirement from $ 10.0 million to $ 2.5 million, (v) modify the interest margin from 4.7 % per annum to 5.0 % per annum and (vi) modify the principal repayment profile to reflect four quarterly installments of $ 5.0 million to repay the loan by the maturity date. All collateral and security arrangements remained in place from the MexMar Original Facility Agreement, including a first priority mortgage on 13 offshore support vessels owned by MexMar. As a result, SEACOR Marine Capital was the sole lender to MexMar under the MexMar Third A&R Facility Agreement. This loan was repaid in full as of September 30, 2023 . Each of the Framework Agreement Transactions and the transactions entered into in connection with the MexMar Third A&R Facility Agreement (the “MexMar Facility Agreement Transactions”) were subject to the oversight of, and received advance approval from, the Audit Committee as related party transactions subject to the Company’s Related Party Transaction Policy. Mr. Miguel recused himself from the Audit Committee and the Board of Directors deliberations with respect to the Framework Agreement Transactions and the Mexmar Facility Agreement Transactions. The Board of Directors received a third party fairness opinion with respect to the Framework Agreement Transactions.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	16. COMMITMENTS AND CONTINGENCIES As of December 31, 2023 , the Company had unfunded capital commitments of $ 15.5 million for miscellaneous vessel equipment, including hybrid battery power systems. Of the unfunded capital commitments, $ 13.5 million is payable during 2024 and $ 2.0 million is payable during 2025. The Company has indefinitely deferred an additional $ 9.2 million of capital commitments with respect to one FSV. In December 2015, the Brazilian Federal Revenue Office issued a tax-deficiency notice to Seabulk Offshore do Brasil Ltda, a wholly owned subsidiary of the Company (“Seabulk Offshore do Brasil”), with respect to certain profit participation contributions (also known as “PIS”) and social security financing contributions (also known as “COFINS”) requirements alleged to be due from Seabulk Offshore do Brasil (“Deficiency Notice”) in respect of the period of January 2011 until December 2012. In January 2016, the Company administratively appealed the Deficiency Notice on the basis that, among other arguments, (i) such contributions were not applicable in the circumstances of a 70 %/ 30 % cost allocation structure, and (ii) the tax inspector had incorrectly determined that values received from outside of Brazil could not be classified as expense refunds. The initial appeal was dismissed by the Brazilian Federal Revenue Office and the Company appealed such dismissal and is currently awaiting an administrative trial. A local Brazilian law has been enacted that supports the Company’s position that such contribution requirements are not applicable, but it is uncertain whether such law will be taken into consideration with respect to administrative proceedings commenced prior to the enactment of the law. Accordingly, the success of Seabulk Offshore do Brasil in the administrative proceedings cannot be assured and the matter may need to be addressed through judicial court proceedings. The potential levy arising from the Deficiency Notice is R$ 23.5 million based on a historical potential levy of R$ 12.87 million (USD $ 4.8 million and USD $ 2.7 million, respectively, based on the exchange rate as of December 31, 2023). In the normal course of its business, the Company becomes involved in various litigation matters including, among others, claims by third parties for alleged property damages and personal injuries. Management has used estimates in determining the Company’s potential exposure to these matters and has recorded reserves in its financial statements related thereto where appropriate. It is possible that a change in the Company’s estimates of that exposure could occur, but the Company does not expect that such changes in estimated costs would have a material effect on the Company’s consolidated financial position, results of operations or cash flows. Certain of the Company’s subsidiaries are participating employers in two industry-wide, multi-employer, defined benefit pension funds in the United Kingdom: the U.K Merchant Navy Officers Pension Fund (“MNOPF”) and the U.K. Merchant Navy Ratings Pension Fund (“MNRPF”). The Company’s participation in the MNOPF began with the acquisition of the Stirling group of companies (the “Stirling Group”) in 2001 and relates to certain officers employed between 1978 and 2002 by the Stirling Group and/or its predecessors. The Company’s participation in the MNRPF also began with the acquisition of the Stirling Group in 2001 and relates to ratings employed by the Stirling Group and/or its predecessors through today. Both of these plans are in deficit positions and, depending upon the results of future actuarial valuations, it is possible that the plans could experience funding deficits that will require the Company to recognize payroll related operating expenses in the periods invoices are received. As of December 31, 2023, all invoices received related to MNOPF and MNRPF have been settled in full. On October 19, 2021, the Company was informed by the MNRPF that two issues had been identified during a review of the MNRPF by the applicable trustee that would potentially give rise to material additional liabilities for the MNRPF. On November 23, 2023, the trustee advised that following the tri-annual valuation, $ 1.5 million (£ 1.2 million) of the potential cumulative funding deficit of the MNRPF was allocated to the Company as a participating employer, including the additional liabilities mentioned above. During 2023, the Company recognized payroll related operating expenses of $ 1.5 million (£ 1.2 million) for its allocated share of the potential cumulative funding deficit, which the Company will be invoiced for during 2024 and 2025.

Major Customers and Segment Inf

Major Customers and Segment Information	12 Months Ended
	Dec. 31, 2023
Notes To Financial Statements [Abstract]
Major Customers and Segment Information	17. MAJOR CUSTOMERS AND SEGMENT INFORMATION During the year ended December 31, 2023, ExxonMobil Corporation (“ExxonMobil”), SEACOR Marine Arabia, a joint venture of which the Company owns 45 % and through which vessels are in service to Saudi Arabian Oil Company, and Azule Energy Angola S.p.A., a joint venture between BP p.l.c. and Eni S.p.A., were responsible for $ 47.7 million or 17 %, $ 43.2 million or 15 % and $ 42.4 million or 15 %, respectively, of the Company’s total consolidated operating revenues from continuing operations. During the year ended December 31, 2022, ExxonMobil and SEACOR Marine Arabia were responsible for $ 39.6 million or 18 % and $ 30.1 million or 14 %, respectively, of the Company’s total consolidated operating revenues from continuing operations. During the year ended December 31, 2021, ExxonMobil and SEACOR Marine Arabia were each responsible for $ 35.2 million or 21 % and $ 29.7 million or 17 %, respectively, of the Company’s total consolidated operating revenues from continuing operations. For the years ended December 31, 2023, 2022 and 2021 , the ten largest customers of the Company accounted for approximately 73 %, 66 % and 81 %, respectively, of the Company’s operating revenues from continuing operations. The loss of one or more of these customers could have a material adverse effect on the Company’s results of operations and cash flows. For the years ended December 31, 2023, 2022 and 2021 , approximately 79 %, 72 % and 88 %, respectively, of the Company’s operating revenues and $ 3.6 million, $ 7.0 million and $ 15.4 million, respectively, of equity in earnings from 50% or less owned companies, net of tax, were derived from its continuing foreign operations. The Company’s offshore support vessels are highly mobile and regularly and routinely move between countries within a geographic region of the world. In addition, these vessels may be redeployed among the geographic regions, subject to flag restrictions, as changes in market conditions dictate. Because of this asset mobility, operating revenues and long-lived assets in any one country and capital expenditures for long-lived assets and gains or losses on asset dispositions and impairments in any one geographic region are not considered meaningful. Direct vessel profit is the Company’s measure of segment profitability when applied to reportable segments. Direct vessel profit is defined as operating revenues less direct operating expenses excluding leased-in equipment expense. The Company utilizes direct vessel profit as its primary financial measure to analyze and compare the operating performance of its regions. The following tables summarize the operating results, capital expenditures and assets of the Company’s reportable segments for the periods indicated (in thousands): United States Africa and Europe Middle East Latin Total For the year ended December 31, 2023 Operating Revenues: Time charter $ 41,850 $ 87,729 $ 66,407 $ 55,399 $ 251,385 Bareboat charter — — — 1,460 1,460 Other marine services 17,678 2,582 4,345 2,061 26,666 59,528 90,311 70,752 58,920 279,511 Direct Costs and Expenses: Operating: Personnel 26,110 20,434 20,786 14,440 81,770 Repairs and maintenance 5,146 9,624 7,109 4,947 26,826 Drydocking 2,314 2,946 ( 99 ) 1,437 6,598 Insurance and loss reserves 3,752 1,727 3,638 839 9,956 Fuel, lubes and supplies 3,697 6,830 3,552 3,108 17,187 Other 1,427 10,072 3,961 1,853 17,313 42,446 51,633 38,947 26,624 159,650 Direct Vessel Profit $ 17,082 $ 38,678 $ 31,805 $ 32,296 $ 119,861 Other Costs and Expenses: Lease expense $ 536 $ 1,498 $ 360 $ 354 2,748 Administrative and general 49,183 Depreciation and amortization 14,685 15,346 14,760 9,030 53,821 105,752 Gains on asset dispositions and impairments, net 21,409 Operating income $ 35,518 As of December 31, 2023 Property and Equipment: Historical cost $ 209,262 $ 272,272 $ 267,079 $ 170,210 $ 918,823 Accumulated depreciation ( 99,137 ) ( 93,045 ) ( 94,708 ) ( 37,251 ) ( 324,141 ) $ 110,125 $ 179,227 $ 172,371 $ 132,959 $ 594,682 Total Assets (1) $ 142,264 $ 215,158 $ 199,174 $ 152,427 $ 709,023 (1) Total Assets exclude $ 71.3 million of corporate assets. United States Africa and Europe Middle East Latin America Total For the year ended December 31, 2022 Operating Revenues: Time charter $ 51,272 $ 60,060 $ 52,080 $ 40,122 $ 203,534 Bareboat charter — — — 1,374 1,374 Other marine services 9,528 ( 163 ) 762 2,290 12,417 60,800 59,897 52,842 43,786 217,325 Direct Costs and Expenses: Operating: Personnel 25,201 16,436 22,376 13,769 77,782 Repairs and maintenance 7,049 9,229 8,111 7,107 31,496 Drydocking 8,978 2,339 6,569 274 18,160 Insurance and loss reserves 4,831 1,178 2,838 1,115 9,962 Fuel, lubes and supplies 3,345 8,022 5,089 2,833 19,289 Other 1,235 7,175 4,633 2,253 15,296 50,639 44,379 49,616 27,351 171,985 Direct Vessel Profit $ 10,161 $ 15,518 $ 3,226 $ 16,435 $ 45,340 Other Costs and Expenses: Lease expense $ 998 $ 1,691 $ 156 $ 1,024 3,869 Administrative and general 40,911 Depreciation and amortization 17,444 13,708 16,331 8,474 55,957 100,737 Gains on asset dispositions and impairments, net 1,398 Operating loss $ ( 53,999 ) As of December 31, 2022 Property and Equipment: Historical cost $ 232,740 $ 285,303 $ 286,745 $ 162,895 $ 967,683 Accumulated depreciation ( 101,503 ) ( 92,030 ) ( 89,444 ) ( 27,801 ) ( 310,778 ) $ 131,237 $ 193,273 $ 197,301 $ 135,094 $ 656,905 Total Assets (1) $ 174,081 $ 211,371 $ 215,497 $ 150,650 $ 751,599 (1) Total Assets exclude $ 64.0 million of corporate assets. United States Africa and Europe, Continuing Operations Middle East Latin America Total For the year ended December 31, 2021 Operating Revenues: Time charter $ 15,487 $ 44,268 $ 53,146 $ 46,934 $ 159,835 Bareboat charter 1,549 — — 2,484 4,033 Other marine services 3,607 ( 1,338 ) 526 4,278 7,073 20,643 42,930 53,672 53,696 170,941 Direct Costs and Expenses: Operating: Personnel 8,836 13,903 22,191 14,990 59,920 Repairs and maintenance 3,394 6,772 6,701 7,250 24,117 Drydocking 2,082 1,159 2,639 467 6,347 Insurance and loss reserves 2,632 1,353 2,481 2,201 8,667 Fuel, lubes and supplies 1,204 4,109 3,459 3,261 12,033 Other 648 5,815 6,158 3,701 16,322 18,796 33,111 43,629 31,870 127,406 Direct Vessel Profit $ 1,847 $ 9,819 $ 10,043 $ 21,826 $ 43,535 Other Costs and Expenses: Lease expense $ 2,621 $ 1,281 $ 472 $ 1,711 6,085 Administrative and general 37,639 Depreciation and amortization 15,712 12,856 17,985 10,842 57,395 101,119 Gains on asset dispositions and impairments, net 20,436 Operating loss $ ( 37,148 ) As of December 31, 2021 Property and Equipment: Historical cost $ 240,717 $ 218,544 $ 340,225 $ 208,594 $ 1,008,080 Accumulated depreciation ( 115,088 ) ( 69,310 ) ( 85,683 ) ( 32,247 ) ( 302,328 ) $ 125,629 $ 149,234 $ 254,543 $ 176,347 $ 705,752 Total Assets (1) $ 148,753 $ 167,185 $ 256,533 $ 250,594 $ 823,065 (1) Total Assets exclude $ 89.4 million of corporate assets.

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2023
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	18. DISCONTINUED OPERATIONS On January 12, 2021, the Company completed the sale of Windcat Workboats, which was previously classified as assets held for sale as of the end of the fourth quarter 2020. The Company has no continuing involvement in this business, which at the time of sale was considered a strategic shift in the Company’s operations. During the first twelve days of 2021, the Company recognized $ 0.2 million in net income from operations of Windcat Workboats that was utilized to calculate the gain on the sale of Windcat Workboats (see “Note 3. Equipment Acquisitions and Dispositions”). Summarized selected operating results of the Company’s assets held for sale and discontinued operations were as follows for the years ended December 31, (in thousands): 2020 Assets from Discontinued Operations: Current assets $ 10,138 Net property and equipment 34,580 Non-current assets 5,517 50,235 Liability from Discontinued Operations: Current liabilities 2,418 Long-term liabilities 28,509 $ 30,927 Windcat Workboats 2021 Operating Revenues: Time charter $ 903 Other revenue 70 973 Costs and Expenses: Operating 578 Direct Vessel Profit 395 General and Administrative Expenses 238 Lease Expense 24 Depreciation — Operating Income 133 Other Income (Expense) Interest income 2 Interest expense ( 39 ) Foreign currency translation gain (loss) 89 Other, net — 52 Operating Income Before Equity Earnings of 50% or 185 Income Tax Benefit — Operating Income Before Equity Earnings of 50% or 185 Equity in (Losses) Earnings of 50% or Less Owned Companies, ( 16 ) Net Income from Discontinued Operations $ 169

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	19. SUBSEQUENT EVENTS The Company has evaluated subsequent events through the filing of this Annual Report on Form 10-K and determined that there have been no material events that have occurred that are not properly recognized and/or disclosed in the consolidated financial statements.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2023
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	SEACOR MARINE HOLDINGS INC. SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS For the Years Ended December 31, 2023, 2022 and 2021 (in thousands) Description Balance Reserves Acquired Charges Deductions Balance Year Ended December 31, 2023 Allowance for credit loss reserves (deducted from trade and notes receivable) $ 1,650 $ — $ 3,519 $ ( 626 ) $ 4,543 Year Ended December 31, 2022 Allowance for credit loss reserves (deducted from trade and notes receivable) $ 1,312 $ — $ 489 $ ( 151 ) $ 1,650 Year Ended December 31, 2021 Allowance for credit loss reserves (deducted from trade and notes receivable) $ 582 $ 3 $ 863 $ ( 136 ) $ 1,312

Nature of Operations and Acco_2

Nature of Operations and Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Nature of Operations and Segmentation	Nature of Operations and Segmentation. The consolidated financial statements include the accounts of SEACOR Marine Holdings Inc. (“SEACOR Marine”), and its consolidated subsidiaries (collectively referred to as the “Company”). The Company provides global marine and support transportation services to offshore energy facilities worldwide. The Company operates and manages a diverse fleet of offshore support vessels that (i) deliver cargo and personnel to offshore installations, including offshore wind farms, (ii) assist offshore operations for production and storage facilities, (iii) provide construction, well work-over, offshore wind farm installation and decommissioning support, (iv) carry and launch equipment used underwater in drilling and well installation, maintenance, inspection and repair and (v) handle anchors and mooring equipment for offshore rigs and platforms. Additionally, the Company's vessels provide emergency response services and accommodations for technicians and specialists. Accounting standards require public business enterprises to report information about each of their operating business segments that exceed certain quantitative thresholds or meet certain other reporting requirements. Operating business segments have been defined as a component of an enterprise about which separate financial information is available and is evaluated regularly by the chief operating decision maker in assessing performance. Upon the Company’s sale of Windcat Workboats Holdings Limited (“Windcat Workboats”) on January 12, 2021, the Company’s European operations were no longer analyzed by the chief operating decision maker on a standalone basis but rather as part of the Africa and Europe segment. As a result, for purposes of segment reporting, European operations are now combined with the Africa segment and reported as a combined segment and prior period information has been conformed to the new consolidated reporting segment. The Company has identified the following four principal geographic regions as its reporting segments: United States, primarily Gulf of Mexico. As of December 31, 2023 , 13 vessels were located in this region, including 11 owned and two managed. The Company’s vessels in this market support oil and natural gas exploration and production activities, seasonal construction, decommissioning and diving support operations, as well as the construction and maintenance of offshore wind farms in the Northeast of the U.S. Africa and Europe, continuing operations. As of December 31, 2023 , 19 vessels were located in this region, including 18 owned and one leased-in. The Company’s vessels in this market generally support projects for major oil companies, primarily in Angola, Nigeria and the North Sea. Middle East and Asia. As of December 31, 2023 , 16 vessels were located in this region, including 15 owned and one managed . The Company’s vessels in this area generally support exploration, personnel transport and seasonal construction activities in Saudi Arabia, United Arab Emirates, Qatar, Egypt and Israel. Latin America. As of December 31, 2023 , ten owned vessels were located in this region. The Company’s vessels in this area generally provide support for exploration and production activities primarily in Mexico, Guyana and Trinidad and Tobago. From time to time, the Company’s vessels also work in Brazil and Colombia.
Basis of Consolidation	Basis of Consolidation. The consolidated financial statements include the accounts of SEACOR Marine and its controlled subsidiaries. Control is generally deemed to exist if the Company has greater than 50 % of the voting rights of a subsidiary. All significant intercompany accounts and transactions are eliminated in the combination and consolidation. Noncontrolling interests in consolidated subsidiaries are included in the consolidated balance sheets as a separate component of equity. The Company reports consolidated net income (loss) inclusive of both the Company’s and the noncontrolling interests’ share, as well as the amounts of consolidated net income (loss) attributable to each of the Company and the noncontrolling interests. If a subsidiary is deconsolidated upon a change in control, any retained noncontrolling equity investment in the former controlled subsidiary is measured at fair value and a gain or loss is recognized in net income (loss) based on such fair value. If a subsidiary is consolidated upon the business acquisition of controlling interests by the Company, any previous noncontrolled equity investment in the subsidiary is measured at fair value and a gain or loss is recognized in net income (loss) based on such fair value. The Company employs the equity method of accounting for investments in 50% or less owned companies that it does not control but has the ability to exercise significant influence over the operating and financial policies of the business venture. Significant influence is generally deemed to exist if the Company has between 20 % and 50 % of the voting rights of a business venture but may exist when the Company’s ownership percentage is less than 20%. In certain circumstances, the Company may have an economic interest in excess of 50% but may not control and consolidate the business venture. Conversely, the Company may have an economic interest less than 50% but may control and consolidate the business venture. The Company reports its investments in and advances to these business ventures in the accompanying consolidated balance sheets as investments, at equity, and advances to 50% or less owned companies. The Company reports its share of earnings from investments in 50% or less owned companies in the accompanying consolidated statements of income (loss) as equity in earnings of 50% or less owned companies, net of tax. Certain reclassifications were made to previously reported amounts in the consolidated financial statements and notes thereto to make them consistent with the current period presentation.
Use of Estimates	Use of Estimates. The preparation of financial statements in conformity with accounting principles generally accepted in the United States (“U.S.”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from estimates and those differences may be material.
Revenue Recognition	Revenue Recognition. The Company contracts with various customers to carry out management services for vessels as agents for and on behalf of ship owners. These services include crew management, technical management, commercial management, insurance arrangements, sale and purchase of vessels, provisions and bunkering. As the manager of the vessels, the Company undertakes to use its best endeavors to provide the agreed management services as agents for and on behalf of the owners in accordance with sound ship management practice and to protect and promote the interest of the owners in all matters relating to the provision of services thereunder. The Company also contracts with various customers to carry out management services regarding engineering for vessel construction and vessel conversions. The vast majority of the ship management agreements span one to three years and are typically billed on a monthly basis. The Company transfers control of the service to the customer and satisfies its performance obligation over the term of the contract, and therefore recognizes revenue over the term of the contract while related costs are expensed as incurred. Revenue that does not meet these criteria is deferred until the criteria is met and is considered a contract liability and is recognized as such. Contract liabilities, which are included in unearned revenue in the accompanying consolidated balance sheets, for the years ended December 31 were as follows (in thousands): 2023 2022 2021 Balance at beginning of year $ 2,333 $ 1,606 $ 4,452 Unearned revenues during the year 6,501 4,288 10,167 Revenues recognized during the year ( 8,147 ) ( 3,561 ) ( 13,013 ) Balance at end of year $ 687 $ 2,333 $ 1,606 As of December 31, 2023, December 31, 2022 and December 31, 2021 , the Company had unearned revenue of $ 0.7 million, $ 2.3 million and $ 1.6 million, respectively, primarily related to mobilization of vessels. The Company earns revenue primarily from the time charter and bareboat charter of vessels to customers. Since the Company charges customers based upon daily rates of hire, vessel revenues are recognized on a daily basis throughout the contract period. Under a time charter, the Company provides a vessel to a customer and is responsible for all operating expenses, typically excluding fuel. Under a bareboat charter, the Company provides a vessel to a customer and the customer assumes responsibility for all operating expenses and assumes all risks of operation. In the U.S. Gulf of Mexico, time charter durations and rates are typically established in the context of master service agreements that govern the terms and conditions of the charter. In the Company’s operating areas, contracts or charters vary in length from several days to multi-year periods. Many of the Company’s contracts and charters include cancellation clauses without early termination penalties. As a result of cancellations, options and frequent renewals, the stated duration of charters may not correlate with the length of time the vessel is contracted for to provide services to a particular customer. During the year ended December 31, 2023, the Company recognized an aggregate amount of business interruption insurance recoveries of $ 6.5 million included in operating revenues in the accompanying consolidated statements of income (loss). Direct Operating Expenses. Direct operating costs and expenses, other than leased-in expense, consist primarily of costs such as personnel; repairs and maintenance; drydocking; insurance and loss reserves; fuel, lubes and supplies; and other vessel expenses, which include costs such as brokers’ commissions, communication costs, expenses incurred in mobilizing vessels between geographic regions, third party ship management fees, freight expenses, and customs and importation duties. Direct operating costs are expensed as incurred.
Direct Operating Expenses	Direct Operating Expenses. Direct operating costs and expenses, other than leased-in expense, consist primarily of costs such as personnel; repairs and maintenance; drydocking; insurance and loss reserves; fuel, lubes and supplies; and other vessel expenses, which include costs such as brokers’ commissions, communication costs, expenses incurred in mobilizing vessels between geographic regions, third party ship management fees, freight expenses, and customs and importation duties. Direct operating costs are expensed as incurred.
Cash Equivalents	Cash Equivalents. The Company considers all highly liquid investments, with an original maturity of three months or less from the date purchased, to be cash equivalents. Cash equivalents consist of U.S. treasury securities, money market instruments, time deposits and overnight investments. A portion of the Company’s cash is maintained at federally insured financial institutions. The deposits held at these institutions are in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institution in which those deposits are held.
Restricted Cash	Restricted Cash. Restricted cash primarily relates to banking facility requirements. For the years ended December 31, cash, cash equivalents and restricted cash consists of: 2023 2022 Cash $ 67,455 $ 39,963 Restricted cash 16,676 3,082 Total $ 84,131 $ 43,045
Trade and Other Receivables and Allowance for Credit Losses	Trade and Other Receivables and Allowance for Credit Losses. Customers are primarily major integrated national, international oil companies, large independent oil and natural gas exploration and production companies and established wind farm construction companies. Customers are granted credit on a short-term basis and the related credit risks are minimal. Other receivables consist primarily of operating expenses the Company incurs in relation to vessels it manages for other entities, as well as insurance and income tax receivables, but excludes our short-term note receivable. The Company routinely reviews its receivables and makes provisions for expected credit losses utilizing the Current Expected Credit Losses model (“CECL”). The CECL model utilizes a lifetime expected credit loss measurement objective for the recognition of credit losses for loans and other receivables at the time the financial asset is originated or acquired. However, those provisions are estimates and actual results may materially differ from those estimates. Trade receivables that are deemed uncollectible and are removed from accounts receivable and the allowance for credit losses when collection efforts have been exhausted.
Derivative Instruments	Derivative Instruments. The Company accounts for derivatives through the use of a fair value concept whereby all of the Company’s derivative positions are stated at fair value in the accompanying consolidated balance sheets. Realized and unrealized gains and losses on derivatives not designated as hedges are reported in the accompanying consolidated statements of income (loss) as Derivative gains (losses), net. Realized and unrealized gains and losses on derivatives designated as fair value hedges are recognized as corresponding increases or decreases in the fair value of the underlying hedged item to the extent they are effective, with any ineffective portion reported in the accompanying consolidated statements of income (loss) as Derivative gains (losses), net, and related cash flows are classified in the same category on the cash flow statement as the cash flows from the items being hedged. Realized and unrealized gains and losses on derivatives designated as cash flow hedges are reported as a component of other comprehensive income (loss) in the accompanying consolidated statements of comprehensive income (loss) to the extent they are effective and reclassified into earnings on the same line item associated with the hedged transaction and in the same period the hedged transaction affects earnings and related cash flows are classified in the same category on the cash flow statement as the cash flows from the items being hedged. Any ineffective portions of cash flow hedges are reported in the accompanying consolidated statements of income (loss) as Derivative gains (losses), net. Realized and unrealized gains and losses on derivatives designated as cash flow hedges that are entered into by the Company’s 50% or less owned companies are also reported as a component of the Company’s other comprehensive income (loss) in proportion to the Company’s ownership percentage, with reclassifications and ineffective portions being included in Equity in earnings of 50% or less owned companies, net of tax, in the accompanying consolidated statements of income (loss).
Concentrations of Credit Risk	Concentrations of Credit Risk. The Company is exposed to concentrations of credit risk associated with its cash and cash equivalents, restricted cash and derivative instruments. The Company minimizes its credit risk relating to these positions by monitoring the financial condition of the financial institutions and counterparties involved and by primarily conducting business with large, well-established financial institutions and diversifying its counterparties. The Company does not currently anticipate nonperformance by any of its significant counterparties. The Company is also exposed to concentrations of credit risk relating to its receivables due from customers described above. The Company does not generally require collateral or other security to support its outstanding receivables. The Company minimizes its credit risk relating to receivables by performing ongoing credit evaluations and, to date, credit losses have not been material.
Inventories	Inventories. Inventories, which consist of fuel and supplies, are stated at the lower of cost (using the first-in, first-out method) or net realizable value. The Company records write-downs, as needed, to adjust the carrying amount of inventories to the lower of cost or net realizable value. In the years ended December 31, 2023, 2022 and 2021 , there were no inventory reserves.
Property and Equipment	Property and Equipment. Equipment, stated at cost, is depreciated using the straight-line method over the estimated useful life of the asset to an estimated salvage value. With respect to each class of asset, the estimated useful life is based upon a newly built asset being placed into service and represents the time period beyond which it is typically not justifiable for the Company to continue to operate the asset in the same or similar manner. From time to time, the Company may acquire older vessels that have already exceeded the Company’s useful life policy, in which case the Company depreciates such assets based on its best estimate of remaining useful life, typically the next survey or certification date. As of December 31, 2023 , the estimated useful life of the Company’s new offshore support vessels was 20 years. The Company’s property and equipment as of December 31 was as follows (in thousands): Historical (1) Accumulated Net Book 2023 Offshore support vessels: AHTS (2) $ 12,112 $ ( 4,578 ) $ 7,534 FSV (3) 340,411 ( 142,096 ) 198,315 PSV (4) 301,461 ( 53,100 ) 248,361 Liftboats 243,295 ( 103,459 ) 139,836 General machinery and spares 9,343 ( 9,161 ) 182 Other (5) 12,201 ( 11,747 ) 454 $ 918,823 $ ( 324,141 ) $ 594,682 2022 Offshore support vessels: AHTS (2) $ 27,281 $ ( 18,139 ) $ 9,142 FSV (3) 354,473 ( 130,599 ) 223,874 PSV (4) 295,875 ( 36,112 ) 259,763 Specialty 3,163 ( 3,138 ) 25 Liftboats 264,142 ( 102,156 ) 161,986 General machinery and spares 10,148 ( 8,565 ) 1,583 Other (5) 12,601 ( 12,069 ) 532 $ 967,683 $ ( 310,778 ) $ 656,905 (1) Includes property and equipment acquired in business acquisitions at acquisition date fair value and net of the impact of recognized impairment charges. Some of the Company’s vessels are pledged as security for certain loans. (2) Anchor Handling Towing Supply vessels (“AHTS”). (3) Fast support vessels (“FSVs”). (4) Platform support vessels (“PSVs”). (5) Includes buildings, leasehold improvements, vehicles and other property and equipment. Depreciation and amortization expense totaled $ 53.8 million, $ 56.0 million and $ 57.4 million in 2023, 2022 and 2021 , respectively. There was no depreciation and amortization expense from discontinued operations in 2023, 2022 or 2021. Equipment maintenance and repair costs and the costs of routine overhauls, drydockings and inspections performed on vessels and equipment are charged to operating expense as incurred. Expenditures that extend the useful life or improve the marketing and commercial characteristics of equipment as well as major renewals and improvements to other properties are capitalized. Certain interest costs incurred during the construction of equipment are capitalized as part of the assets’ carrying values and are amortized over such assets’ estimated useful lives. There was no capitalized interest recognized in 2023 or 2022 . Capitalized interest totaled $ 0.3 million in 2021 .
Assets Held for Sale	Assets Held for Sale. As of December 31, 2023 , one AHTS previously included in the Africa and Europe segment, with a carrying value of $ 0.5 million, was classified as assets held for sale as the Company expects to sell the vessel within one year.
Impairment of Long-Lived Assets and Impairment of 50% or Less Owned Companies	Impairment of Long-Lived Assets. The Company performs an impairment analysis of long-lived assets used in operations when indicators of impairment are present. These indicators may include a significant decrease in the market price of a long-lived asset or asset group, a significant adverse change in the extent or manner in which a long-lived asset or asset group is being used or in its physical condition, or a current period operating or cash flow loss combined with a history of operating or cash flow losses or a forecast that demonstrates continuing losses associated with the use of a long-lived asset or asset group. If the carrying values of the assets are not recoverable, as determined by their estimated future undiscounted cash flows, the estimated fair value of the assets or asset groups are compared to their current carrying values and impairment charges are recorded if the carrying value exceeds fair value. As a result of the difficult conditions experienced in the offshore oil and natural gas markets beginning in the second half of 2014 and the corresponding reductions in utilization and rates per day worked of its fleet, the Company identified indicators of impairment and recognized impairment charges primarily associated with its AHTS fleet, its liftboat fleet, certain specialty vessels and vessels removed from service. When reviewing its fleet for impairment, the Company groups vessels with similar operating and marketing characteristics, including cold-stacked vessels expected to return to active service, into vessel classes. All other vessels, including vessels retired and removed from service, are evaluated for impairment on a vessel by vessel basis. During the year ended December 31, 2023 , the Company recorded impairment charges totaling $ 0.7 million for one leased-in AHTS to adjust for indicative future cash flows and the cost to return the vessel to its owner. During the year ended December 31, 2022 , the Company recorded impairment charges totaling $ 2.9 million. The Company recorded impairment charges of $ 0.9 million for one FSV classified as held for sale and sold during 2022. In addition, the Company recorded impairment charges of $ 0.7 million for one leased-in AHTS as it is not expected to return to active service during its remaining lease term. Additionally, the Company recorded impairment charges of $ 1.3 million for other equipment and classified such equipment as assets held for sale as the Company expects to sell the equipment within one year. The impairment charges for the assets held for sale are included in (losses) gains on asset dispositions and impairments in the accompanying consolidated statements of income (loss). There were no impairments of other owned or leased-in vessels. The Company’s other vessel classes and other individual vessels in active service and cold-stacked status, for which no impairment was deemed necessary, have generally experienced a less severe decline in utilization and rates per day worked based on specific market factors. The market factors include vessels with more general utility to a broad range of customers (e.g., FSVs), vessels required for customers to meet regulatory mandates and operating under multiple year contracts or vessels that service customers outside of the offshore oil and natural gas market. For vessel classes and individual vessels with indicators of impairment as of December 31, 2023, the Company estimated that their future undiscounted cash flows exceeded their current carrying values. However, the Company’s estimates of future undiscounted cash flows are highly subjective as utilization and rates per day worked are uncertain, especially in light of the continued volatility in commodity prices as well as the timing and cost of reactivating cold-stacked vessels. If market conditions decline, changes in the Company’s expectations on future cash flows may result in recognizing additional impairment charges related to its long-lived assets in future periods. For any vessel or vessel class that has indicators of impairment and is deemed not recoverable through future operations, the Company determines the fair value of the vessel or vessel class. If the fair value determination is less than the carrying value of the vessel or vessel class, an impairment is recognized to reduce the carrying value to fair value. Fair value determination is primarily accomplished by obtaining independent valuations of vessel or vessel classes from qualified third party appraisers. Impairment of 50% or Less Owned Companies. Investments in 50% or less owned companies are reviewed periodically to assess whether there is an other-than-temporary decline in the carrying value of the investment. In its evaluation, the Company considers, among other items, recent and expected financial performance and returns, impairments recorded by the investee and the capital structure of the investee. When the Company determines the estimated fair value of an investment is below carrying value and the decline is other-than-temporary, the investment is written down to its estimated fair value. Actual results may vary from the Company’s estimates due to the uncertainty regarding projected financial performance, the severity and expected duration of declines in value and the available liquidity in the capital markets to support the continuing operations of the investee, among other factors. Although the Company believes its assumptions and estimates are reasonable, the investee’s actual performance compared with the estimates could produce different results and lead to additional impairment charges in future periods. No impairment charges of investments in 50% or less owned companies were incurred for the years ended December 31, 2023, 2022 and 2021 .
Business Combinations	Business Combinations. For acquisitions constituting a business acquisition, the Company recognizes 100% of the fair value of assets acquired, liabilities assumed, and noncontrolling interests when the acquisition constitutes a change in control of the acquired entity. Shares issued in consideration for a business combination, contingent consideration arrangements and pre-acquisition loss and gain contingencies are all measured and recorded at their acquisition-date fair value. Subsequent changes to fair value of contingent consideration arrangements are generally reflected in earnings. Acquisition-related transaction costs are expensed as incurred and any changes in an acquirer’s existing income tax valuation allowances and tax uncertainty accruals are recorded as an adjustment to income tax expense. The operating results of entities acquired are included in the accompanying consolidated statements of income (loss) from the date of acquisition. If an acquisition of an asset or group of assets does not meet the definition of a business, the transaction is accounted for as an asset acquisition. The assets are measured based on their cost to the Company, including transaction costs. The acquisition cost is then allocated to the assets acquired based on their relative fair values.
Debt Discount and Issue Costs	Debt Discount and Issue Costs . Debt discounts and costs incurred in connection with the issuance of debt are amortized over the life of the related debt using the effective interest rate method for term loans and straight-line method for revolving credit facilities and are included in interest expense in the accompanying consolidated statements of income (loss).
Self-insurance Liabilities	Self-insurance Liabilities . The Company maintains marine hull, liability and war risk, general liability, workers compensation and other insurance customary in the industry in which it operates. Both the marine hull and liability policies have annual aggregate deductibles. Marine hull annual aggregate deductibles are accrued as claims are incurred while marine liability annual aggregate deductibles are accrued based on historical loss experience. Exposure to the health benefit plans are limited by maintaining stop-loss and aggregate liability coverage. To the extent that estimated self-insurance losses, including the accrual of annual aggregate deductibles, differ from actual losses realized, the Company’s insurance reserves could differ significantly and may result in either higher or lower insurance expense in future periods.
Income Taxes	Income Taxes . Deferred income tax assets and liabilities have been provided in recognition of the income tax effect attributable to the book and tax basis differences of assets and liabilities reported in the consolidated financial statements. Deferred tax assets or liabilities are provided using the enacted tax rates expected to apply to taxable income in the periods in which they are expected to be settled or realized. Interest and penalties relating to uncertain tax positions are recognized in interest expense and administrative and general, respectively, in the accompanying consolidated statements of income (loss). The Company records a valuation allowance to reduce its deferred tax assets if it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Global Intangible Low Taxed Income (“GILTI”) regime effectively imposes a minimum tax on worldwide foreign earnings and subjects U.S. shareholders of controlled foreign corporations (“CFCs”) to current taxation on certain income earned through a CFC. The Company has made the policy election to record any liability associated with GILTI in the period in which it is incurred. In the normal course of business, the Company may be subject to challenges from tax authorities regarding the amount of taxes due for the Company. These challenges may alter the timing or amount of taxable income or deductions. As part of the calculation of income tax expense, the Company determines whether the benefits of its tax positions are at least more likely than not of being sustained based on the technical merits of the tax position. For tax positions that are more likely than not of being sustained, the Company accrues the largest amount of the tax benefit that is more likely than not of being sustained. Such accruals require management to make estimates and judgments with respect to the ultimate outcome of its tax benefits and actual results could vary materially from these estimates.
Foreign Currency Translation	Foreign Currency Translation. The assets, liabilities and results of operations of certain consolidated subsidiaries are measured using their functional currency, which is the currency of the primary foreign economic environment in which they operate. Upon consolidating these subsidiaries with the Company, their assets and liabilities are translated to U.S. dollars at currency exchange rates as of the consolidated balance sheet dates and their revenues and expenses are translated at the weighted average currency exchange rates during the applicable reporting periods. Translation adjustments resulting from the process of translating these subsidiaries’ financial statements are reported in other comprehensive income in the accompanying consolidated statements of comprehensive income (loss). Foreign Currency Transactions. Certain consolidated subsidiaries enter into transactions denominated in currencies other than their functional currency. Gains and losses resulting from changes in currency exchange rates between the functional currency and the currency in which a transaction is denominated are included in foreign currency losses, net in the accompanying consolidated statements of income (loss) in the period in which the currency exchange rates change.
Accumulated Other Comprehensive (Loss) Income	Accumulated Other Comprehensive (Loss) Income. The components of accumulated other comprehensive (loss) income were as follows (in thousands): SEACOR Marine Holdings Inc. Noncontrolling Interests Foreign Derivative (Losses) Gains on Cash Flow Total Foreign Derivative Other Year Ended December 31, 2020 $ 6,797 $ ( 4,007 ) $ 2,790 $ ( 1,445 ) $ ( 11 ) $ 1,242 Other comprehensive income 3,986 1,279 5,265 — — 5,265 Income tax (expense) — — — — — — Year Ended December 31, 2021 10,783 ( 2,728 ) 8,055 ( 1,445 ) ( 11 ) $ 5,265 Other comprehensive loss ( 4,451 ) 3,243 ( 1,208 ) — — $ ( 1,208 ) Income tax benefit (expense) — — — — — — Year Ended December 31, 2022 6,332 515 6,847 ( 1,445 ) ( 11 ) $ ( 1,208 ) Other comprehensive income 1,245 ( 515 ) 730 — — 730 Income tax benefit (expense) — — — — — — Year Ended December 31, 2023 $ 7,577 $ — $ 7,577 $ ( 1,445 ) $ ( 11 ) $ 730
Earnings (Loss) Per Share	Earnings (Loss) Per Share. Basic earnings/loss per share of the common stock, par value $ 0.01 per share, of SEACOR Marine (“Common Stock”) is computed based on the weighted average number of shares of Common Stock and warrants to purchase Common Stock at an exercise price of $ 0.01 per share (“Warrants”) issued and outstanding during the relevant periods. The Warrants are included in the basic earnings/loss per share of Common Stock because the shares issuable upon exercise of the Warrants are issuable for de minimis cash consideration and therefore not anti-dilutive. Diluted earnings/loss per share of Common Stock is computed based on the weighted average number of shares of Common Stock and Warrants issued and outstanding plus the effect of other potentially dilutive securities through the application of the treasury stock method and the if-converted method that assumes all shares of Common Stock have been issued and outstanding during the relevant periods pursuant to the conversion of the Old Convertible Notes and the New Convertible Notes (as defined in “Note 6. Long-Term Debt”) unless anti-dilutive. For the years ended December 31, 2023 and 2022, diluted loss per common share of the Company excluded 2,978,274 shares issuable upon the conversion of the New Convertible Notes as the effect of their inclusion in the computation would be anti-dilutive. For the year ended December 31, 2021, diluted earnings per common share of the Company excluded 2,907,500 shares issuable upon the conversion of the Old Convertible Notes as the effect of their inclusion in the computation would be anti-dilutive. In addition, for the years ended December 31, 2023, 2022 and 2021 , diluted (loss) earnings per common share of the Company excluded 1,642,084 shares, 1,682,193 shares and 1,112,256 shares, respectively, of restricted stock and 1,026,031 , 1,026,865 and 1,061,357 of outstanding stock options as the effect of their inclusion in the computation would be anti-dilutive. For the year ended December 31, 2021, diluted earnings per share of Common Stock of the Company included 50,834 shares of restricted stock as the effect of their inclusion in the computation is dilutive, with no related income effect. In 2023, 2022 and 2021 , the Company issued 156,620 , 184,930 and 157,455 performance share awards, of which 156,620 were not considered outstanding as of December 31, 2023 . These performance share awards are not considered outstanding until such time as they would be probable of being exercised, therefore they were not included in the computation of earnings (loss) per share.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards
Recently Issued Accounting Standards	Recently Issued Accounting Standards. On December 14, 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which requires public entities to disclose information about their effective tax rate reconciliation and information on income taxes paid. The guidance is effective for fiscal years beginning after December 15, 2024. While early adoption is permitted, the Company has determined it will not early adopt the standard. The Company has not yet determined the impact that the adoption of the standard will have on the Company’s consolidated financial position, results of operations and disclosures. On November 27, 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which requires public entities to disclose information about their reportable segments’ significant expenses on an interim and annual basis. The guidance is effective for fiscal years beginning after December 15, 2023 and interim periods within the fiscal years beginning after December 15, 2024. While early adoption is permitted, the Company has determined it will not early adopt the standard. The Company has not yet determined the impact that the adoption of the standard will have on the Company’s consolidated financial position, results of operations and disclosures. On October 9, 2023, the FASB issued ASU 2023-06, Disclosure Improvements: Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative, which amends the disclosure or presentation requirements related to various subtopics in the FASB Accounting Standards Codification. The effective date is contingent on when the SEC removes the related disclosure from Regulation S-X or Regulation S-K, with early adoption prohibited. The Company does not believe the adoption of the standard will have a material effect on the disclosures included herein.

Nature of Operations and Acco_3

Nature of Operations and Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2023
Nature Of Operation And Accounting Policies [Abstract]
Schedule of Deferred Revenues	Revenue that does not meet these criteria is deferred until the criteria is met and is considered a contract liability and is recognized as such. Contract liabilities, which are included in unearned revenue in the accompanying consolidated balance sheets, for the years ended December 31 were as follows (in thousands): 2023 2022 2021 Balance at beginning of year $ 2,333 $ 1,606 $ 4,452 Unearned revenues during the year 6,501 4,288 10,167 Revenues recognized during the year ( 8,147 ) ( 3,561 ) ( 13,013 ) Balance at end of year $ 687 $ 2,333 $ 1,606
Schedule Of Cash Cash Equivalents And Restricted Cash From Continuing Operations	For the years ended December 31, cash, cash equivalents and restricted cash consists of: 2023 2022 Cash $ 67,455 $ 39,963 Restricted cash 16,676 3,082 Total $ 84,131 $ 43,045
Summary of Property and Equipment from Continuing Operations	The Company’s property and equipment as of December 31 was as follows (in thousands): Historical (1) Accumulated Net Book 2023 Offshore support vessels: AHTS (2) $ 12,112 $ ( 4,578 ) $ 7,534 FSV (3) 340,411 ( 142,096 ) 198,315 PSV (4) 301,461 ( 53,100 ) 248,361 Liftboats 243,295 ( 103,459 ) 139,836 General machinery and spares 9,343 ( 9,161 ) 182 Other (5) 12,201 ( 11,747 ) 454 $ 918,823 $ ( 324,141 ) $ 594,682 2022 Offshore support vessels: AHTS (2) $ 27,281 $ ( 18,139 ) $ 9,142 FSV (3) 354,473 ( 130,599 ) 223,874 PSV (4) 295,875 ( 36,112 ) 259,763 Specialty 3,163 ( 3,138 ) 25 Liftboats 264,142 ( 102,156 ) 161,986 General machinery and spares 10,148 ( 8,565 ) 1,583 Other (5) 12,601 ( 12,069 ) 532 $ 967,683 $ ( 310,778 ) $ 656,905 (1) Includes property and equipment acquired in business acquisitions at acquisition date fair value and net of the impact of recognized impairment charges. Some of the Company’s vessels are pledged as security for certain loans. (2) Anchor Handling Towing Supply vessels (“AHTS”). (3) Fast support vessels (“FSVs”). (4) Platform support vessels (“PSVs”). (5) Includes buildings, leasehold improvements, vehicles and other property and equipment.
Schedule of Accumulated Other Comprehensive (Loss) Income	Accumulated Other Comprehensive (Loss) Income. The components of accumulated other comprehensive (loss) income were as follows (in thousands): SEACOR Marine Holdings Inc. Noncontrolling Interests Foreign Derivative (Losses) Gains on Cash Flow Total Foreign Derivative Other Year Ended December 31, 2020 $ 6,797 $ ( 4,007 ) $ 2,790 $ ( 1,445 ) $ ( 11 ) $ 1,242 Other comprehensive income 3,986 1,279 5,265 — — 5,265 Income tax (expense) — — — — — — Year Ended December 31, 2021 10,783 ( 2,728 ) 8,055 ( 1,445 ) ( 11 ) $ 5,265 Other comprehensive loss ( 4,451 ) 3,243 ( 1,208 ) — — $ ( 1,208 ) Income tax benefit (expense) — — — — — — Year Ended December 31, 2022 6,332 515 6,847 ( 1,445 ) ( 11 ) $ ( 1,208 ) Other comprehensive income 1,245 ( 515 ) 730 — — 730 Income tax benefit (expense) — — — — — — Year Ended December 31, 2023 $ 7,577 $ — $ 7,577 $ ( 1,445 ) $ ( 11 ) $ 730

Equipment Acquisitions and Di_2

Equipment Acquisitions and Dispositions (Tables)	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Schedule of Vessel Acquired and Disposed	Deliveries of offshore support vessels for the years ended December 31 were as follows: 2023 2022 2021 (1) FSV 1 — — PSV — 1 1 1 1 1 (1) Excludes five PSVs acquired as part of the OSV Partners Acquisition in 2021. Major equipment dispositions for the years ended December 31 were as follows: 2023 2022 (1) 2021 (2) AHTS — 1 — FSV 1 1 3 PSV — — 1 Liftboats 4 1 1 Specialty 1 — — 6 3 5 (1) Excludes one specialty vessel that was previously removed from service, which was sold in 2023. (2) Excludes four liftboats that were previously removed from service, of which three were sold in 2023 and one was sold in 2022. On January 12, 2021, a wholly owned subsidiary of the Company, completed the sale of the Company’s Windcat Workboats crew transfer vessel (“CTV”) business through the sale of 100% of the equity of Windcat Workboats, a wholly owned subsidiary of the Company (“Windcat” and together with its subsidiaries, the “Windcat Group”), to CMB N.V. (the “Windcat Buyer”) pursuant to a Sale and Purchase Agreement entered into on December 18, 2020. At closing, the Windcat Buyer paid to the Company an aggregate purchase price of £32.8 million. After deducting transaction costs and expenses and giving effect to foreign exchange rate hedges, the Company received net cash proceeds of approximately $42.6 million. The Windcat Buyer also assumed all of the approximately £20.4 million of debt outstanding under Windcat Workboat’s existing revolving credit facility. As of December 31, 2020, the Windcat Group owned a total of 41 CTVs and held interests in an additional five CTVs through its joint ventures, all of which were included in the sale. The Company recognized a gain on the sale of Windcat Workboats of approximately $22.8 million during 2021, calculated as follows: (In Thousands): January 12, 2021 Total Proceeds Received $ 43,797 Transactions Fees and other Costs 1,562 Cash Sold 3,520 Total Net Proceeds 38,715 Less: Net Equity in Windcat Workboats, net of cash sold 15,790 Less: January Income on Discontinued Operations 169 Gain on Sale of Windcat Workboats $ 22,756
Schedule of Gain on Sale of Windcat Workboats	The Company recognized a gain on the sale of Windcat Workboats of approximately $22.8 million during 2021, calculated as follows: (In Thousands): January 12, 2021 Total Proceeds Received $ 43,797 Transactions Fees and other Costs 1,562 Cash Sold 3,520 Total Net Proceeds 38,715 Less: Net Equity in Windcat Workboats, net of cash sold 15,790 Less: January Income on Discontinued Operations 169 Gain on Sale of Windcat Workboats $ 22,756

Investments, at Equity, and A_2

Investments, at Equity, and Advances to 50% or Less Owned Companies (Tables)	12 Months Ended
	Dec. 31, 2023
Schedule of Investments [Abstract]
Equity Method Investments	Investments, at equity, and advances to 50% or less owned companies as of December 31 were as follows (in thousands): Ownership 2023 2022 Seabulk Angola 49.0 % 1,668 1,683 SEACOR Marine Arabia 45.0 % 2,385 1,265 Other 20.0 % — 50.0 % 72 76 $ 4,125 $ 3,024 Combined Condensed Financial Information of Other Investees. Summarized financial information of the Company’s other investees, at equity, as of and for the years ended December 31 was as follows (in thousands): 2023 2022 Current assets $ 29,820 $ 24,699 Noncurrent assets 61 266 Current liabilities 21,008 17,070 Noncurrent liabilities — — 2023 2022 2021 Operating Revenues $ 68,949 $ 133,740 $ 156,579 Costs and Expenses: Operating and administrative 61,294 90,678 139,313 Depreciation 27 21,434 23,524 61,321 112,112 162,837 Operating Income (Loss) $ 7,628 $ 21,628 $ ( 6,258 ) Net Income $ 5,239 $ 15,057 $ 41,798
Schedule of Gain on Sale of Equity Investments	The Company recognized a gain on the sale of MexMar, OVH and other assets of approximately $ 0.8 million, calculated as follows: September 29, 2022 Total Cash Received $ 66,000 51% ownership in SEACOR Marlin Joint Venture 7,000 Hybrid Battery Power System 1,394 Less: Transaction Fees and other Costs 1,159 Total Net Proceeds 73,235 Less: Net Equity in MexMar and OVH Joint Ventures 65,546 Less: Net Book Value of SEACOR Davis 5,507 Less: OVH Note Receivable 1,394 Gain on Sale of MexMar, OVH and Other Assets $ 788

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Summary of Future Minimum Payments For Leases	As of December 31, 2023, future minimum payments for leases for the years ended December 31 were as follows (in thousands): Operating Leases Finance Leases 2024 $ 1,864 $ 36 2025 746 6 2026 459 — 2027 400 — 2028 341 — Years subsequent to 2028 2,873 — 6,683 42 Interest component ( 1,563 ) ( 1 ) 5,120 41 Current portion of long-term lease liabilities 1,591 35 Long-term lease liabilities $ 3,529 $ 6
Summary of Components of Leases Expense	For the years ended December 31, the components of lease expense were as follows (in thousands): 2023 2022 Operating lease costs $ 2,222 $ 3,162 Finance lease costs: Amortization of finance lease asset (1) 468 545 Interest on lease liabilities (2) 202 246 Short-term lease costs 526 707 $ 3,418 $ 4,660 (1) Included in amortization costs in the consolidated statements of income (loss). (2) Included in interest expense in the consolidated statements of income (loss).
Summary of Supplemental Cash Flow Information Related to Leases	For the year ended December 31, 2023, supplemental cashflow information related to leases were as follows (in thousands): 2023 Operating cash flows from operating leases $ 2,362 Financing cash outflows from finance leases 531 Right-of-use assets obtained for operating lease liabilities 499 Right-of-use assets obtained for finance lease liabilities —
Summary of Other Information Related to Leases	For the year ended December 31, 2023, other information related to leases were as follows: 2023 Weighted average remaining lease term, in years - operating leases 10.2 Weighted average remaining lease term, in years - finance leases 1.2 Weighted average discount rate - operating leases 6.7 % Weighted average discount - finance leases 4.0 %

Long-term Debt (Tables)

Long-term Debt (Tables)	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Schedule of Long-term Debt Obligations	The Company’s long-term debt obligations as of December 31 were as follows (in thousands): 2023 2022 Recourse long-term debt (1) : Guaranteed Notes $ 90,000 $ 90,000 New Convertible Notes 35,000 35,000 2023 SMFH Credit Facility (2) 118,950 — 2018 SMFH Credit Facility (2) — 67,910 Sea-Cat Crewzer III Term Loan Facility 14,227 16,703 SEACOR Delta Shipyard Financing (3) 68,647 77,537 SEACOR Alpine Credit Facility (4) 26,200 — SEACOR Alpine Shipyard Financing (4) — 27,790 SEACOSCO Acquisition Debt (2) — 16,205 SEACOR 88/888 Term Loan (2) — 5,500 Tarahumara Shipyard Financing (2) — 5,597 SEACOR Offshore OSV (2) — 16,052 Total recourse long-term debt 353,024 358,294 Non-recourse long-term debt (5) : SEACOR 88/888 Term Loan (2) — 5,500 Total non-recourse long-term debt — 5,500 Total principal due for long-term debt 353,024 363,794 Current portion due within one year ( 28,365 ) ( 61,512 ) Unamortized debt discount ( 32,885 ) ( 37,511 ) Deferred financing costs ( 4,230 ) ( 4,652 ) Long-term debt, less current portion $ 287,544 $ 260,119 (1) Recourse debt represents debt issued by SEACOR Marine and/or its subsidiaries and guaranteed by SEACOR Marine or one of its operating subsidiaries as provided in the relevant debt agreements. (2) Proceeds from the 2023 SMFH Credit Facility, dated September 8, 2023, were used to satisfy in full the 2018 SMFH Credit Facility, the SEACOSCO Acquisition Debt, the SEACOR 88/888 Term Loan, the Tarahumara Shipyard Financing, and the SEACOR Offshore OSV debt. See details below. (3) SEACOR Delta Shipyard Financing includes vessel financing on the eight SEACOR Delta PSVs. See details below. (4) Proceeds from the SEACOR Alpine Credit Facility, dated June 16, 2023, were used to satisfy in full the SEACOR Alpine Shipyard Financing. See details below. (5) Non-recourse debt represents debt issued by one of the Company’s consolidated subsidiaries with no recourse to SEACOR Marine or its other non-obligor operating subsidiaries with respect to the applicable instrument, other than certain limited support obligations as provided in the respective debt agreements, which in aggregate are not considered to be material to the Company’s business and financial condition.
Schedule of Long-term Debt Maturities	The Company’s contractual long-term debt maturities from continuing operations for the years ended December 31 were as follows (in thousands): 2024 $ 28,365 2025 28,605 2026 152,405 2027 27,165 2028 110,257 Years subsequent to 2028 6,227 $ 353,024
Schedule of Gain on Transactions Under Conditional Payoff Agreement	On June 24, 2021, the Company recognized a gain on transactions under the Conditional Payoff Agreement of approximately $ 62.0 million, calculated as follows: (In Thousands): June 24, 2021 Falcon Global USA Term Loan Facility $ 102,349 Falcon Global USA Revolver 15,000 Unamortized debt discount ( 4,600 ) Current Liabilities 112,749 Transaction Fees ( 755 ) Cash Paid ( 27,500 ) Hull and Machinery Insurance Proceeds ( 22,500 ) Gain on Troubled Debt Restructuring $ 61,994

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Schedule of (Loss) Income before Income Tax Expense (Benefit), Domestic and Foreign	(Loss) Income before income tax expense (benefit) and equity in earnings (losses) of 50 % or less owned companies derived from U.S. and foreign companies for the years ended December 31 were as follows (in thousands): 2023 2022 2021 United States $ ( 3,576 ) $ ( 48,037 ) $ 34,955 Foreign ( 335 ) ( 21,881 ) ( 29,425 ) Eliminations ( 160 ) ( 160 ) 1,097 $ ( 4,071 ) $ ( 70,078 ) $ 6,627
Schedule of Components of Income Tax Expense (Benefit)	The components of income tax expense (benefit) for the years ended December 31 were as follows (in thousands): 2023 2022 2021 Current: Federal $ ( 18 ) $ 90 $ — State 47 ( 78 ) 271 Foreign 13,831 8,473 6,362 13,860 8,485 6,633 Deferred: Federal ( 5,062 ) 7 4,892 State 8 90 ( 32 ) Foreign ( 7 ) — — ( 5,061 ) 97 4,860 $ 8,799 $ 8,582 $ 11,493
Schedule of Effective Income Tax Rate Reconciliation	The following table reconciles the difference between the statutory federal income tax rate for the Company and the effective income tax rate for the years ended December 31: 2023 2022 2021 Statutory rate ( 21.0 )% ( 21.0 )% 21.0 % Income (loss) of foreign subsidiaries not includable in U.S. return and foreign withholding tax 223.4 % 20.8 % 141.6 % Non-Deductible Expenses 1.2 % 0.3 % 0.4 % JV equity earnings — % — % 3.8 % Sale of investments in 50 % or less owned companies — % 11.1 % — % 162(m) - Executive compensation 17.8 % — % — % Return to provision — % — % 0.4 % State Taxes 1.1 % — % 2.7 % Subpart F Income 6.6 % 0.7 % 2.0 % Share Award Plans ( 12.9 )% 0.3 % 1.5 % Other — 0.1 % — % Effective Tax Rate 216.2 % 12.3 % 173.4 %
Schedule of Deferred Tax Assets and Liabilities	The components of net deferred income tax liabilities as of December 31 were as follows (in thousands): 2023 2022 Deferred tax liabilities: Property and equipment $ 48,779 $ 56,618 Other 3,533 6,094 Total deferred tax liabilities 52,312 62,712 Deferred tax assets: Federal Net Operating Loss Carryforwards 10,887 14,822 Other 10,632 9,619 21,519 24,441 Valuation Allowance ( 4,925 ) ( 2,508 ) Total deferred tax assets 16,594 21,933 Net deferred tax liabilities $ 35,718 $ 40,779

Derivative Instruments and He_2

Derivative Instruments and Hedging Strategies (Tables)	12 Months Ended
	Dec. 31, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Fair Value of Derivative Assets and Liabilities	The fair values of the Company’s derivative instruments as of December 31 were as follows (in thousands): 2023 2022 Derivative Derivative Derivative Derivative Derivatives designated as hedging instruments: Interest rate swap agreements (cash flow hedges) $ — $ — $ 526 $ — Derivatives not designated as hedging instruments: Forward Exchange Contract $ 608 $ — $ — $ —
Effect of Derivative Instruments on Other Comprehensive Income (Loss)	The following tables reflect amounts recorded in Other Comprehensive Income (Loss) (“OCI”) and amounts reclassified from OCI to revenue and expense for the periods indicated: Gains (Losses) Recognized in OCI on Derivatives Derivatives in Cash Flow Hedging Relationships 2023 2022 2021 Interest rate swap contracts $ 56 $ 1,608 $ 219 Joint venture interest rate swap contracts — 941 ( 588 ) (Gains) Losses Reclassified from OCI into Income Location of (Gains) Losses 2023 2022 2021 Interest expense $ ( 571 ) $ 694 $ 1,648
Schedule of Gains (Losses) on Derivative Instruments not Designated as Hedging Instruments	The Company recognized gains on derivative instruments not designated as hedging instruments for the years ended December 31 as follows (in thousands): Derivative gains (losses), net 2023 2022 2021 Conversion option liability on Old Convertible Notes $ — $ — $ 2 Forward currency exchange, option and future contracts 608 — 390 $ 608 $ — $ 392

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis	The Company’s financial assets and liabilities as of December 31 that are measured at fair value on a recurring basis were as follows (in thousands): Level 1 Level 2 Level 3 2023 ASSETS Derivative instruments $ — $ 608 $ — 2022 LIABILITIES Derivative instruments $ — $ 526 $ —
Schedule of Estimated Fair Values of Financial Assets and Liabilities	The estimated fair values of the Company’s other financial assets and liabilities as of December 31 were as follows (in thousands): Estimated Fair Value Carrying Level 1 Level 2 Level 3 2023 ASSETS Cash, cash equivalents and restricted cash $ 84,131 $ 84,131 $ — $ — LIABILITIES Long-term debt, including current portion 315,909 — 307,653 — 2022 ASSETS Cash, cash equivalents and restricted cash $ 43,045 $ 43,045 $ — $ — LIABILITIES Long-term debt, including current portion 321,631 — 314,979 —

Noncontrolling Interests in S_2

Noncontrolling Interests in Subsidiaries (Tables)	12 Months Ended
	Dec. 31, 2023
Noncontrolling Interest [Abstract]
Schedule of Noncontrolling Interests in the Company's Consolidated Subsidiaries	Noncontrolling interests in the Company’s consolidated subsidiaries as of December 31 were as follows (in thousands): Noncontrolling 2023 2022 VEESEA Holdings Inc. 1.8 % $ 321 $ 321

Share Based Compensation (Table

Share Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Schedule of Equity Incentive Plan Transactions	Transactions in connection with the Company’s Equity Incentive Plans during the years ended December 31 were as follows: 2023 2022 2021 Director Stock Awards Granted 60,938 60,787 189,030 Restricted Stock Activity: Outstanding as of the beginning of year 1,682,193 1,163,090 436,714 Granted 660,307 1,036,605 933,705 Vested ( 685,416 ) ( 514,002 ) ( 202,079 ) Forfeited ( 15,000 ) ( 3,500 ) ( 5,250 ) Outstanding as of the end of year (1) 1,642,084 1,682,193 1,163,090 Stock Option Activity: Outstanding as of the beginning of year 1,026,865 1,061,357 1,120,541 Granted — — — Exercised (2) ( 834 ) ( 34,492 ) — Forfeited (3) — — ( 59,184 ) Outstanding as of the end of year 1,026,031 1,026,865 1,061,357 (1) Excludes 156,620 , 216,172 and 354,964 grants of performance-based stock units as of December 31, 2023, 2022 and 2021 , respectively, that are not considered outstanding until such time that they become probable to vest. (2) The intr insic value of the options exercised was less than $ 0.1 million. (3) Forfeitures in 2021 includes 71,684 options forfeited as of December 31, 2021, netted with an adjustment of 12,500 previously granted.
Schedule of Restricted Stock Transactions	During the year ended December 31, 2023, the number of shares and the weighted average grant price of restricted stock transactions were as follows: Restricted Stock Number of Weighted Average Non-Vested as of December 31, 2022 1,682,193 $ 5.68 Granted 660,307 9.67 Vested ( 685,416 ) 10.12 Forfeited ( 15,000 ) 5.82 Non-Vested as of December 31, 2023 1,642,084 7.53
Schedule of Stock Option Transactions	During the year ended December 31, 2023, the number of shares and the weighted average exercise price on stock option transactions were as follows: Stock Options Number of Weighted Average Outstanding as of December 31, 2022 1,026,865 $ 12.66 Granted — — Exercised ( 834 ) 6.97 Forfeited — — Outstanding as of December 31, 2023 (1) 1,026,031 12.66 Exercisable as of December 31, 2023 (2) 1,026,031 12.66 (1) The weighted average remaining contractual term is 4.8 years and the intrinsic value of the options exercised was $ 1.7 million. (2) The weighted average remaining contractual term is 4.8 years and the intrinsic value of the options exercisable was $ 1.7 million.

Major Customers and Segment I_2

Major Customers and Segment Information (Tables)	12 Months Ended
	Dec. 31, 2023
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	The following tables summarize the operating results, capital expenditures and assets of the Company’s reportable segments for the periods indicated (in thousands): United States Africa and Europe Middle East Latin Total For the year ended December 31, 2023 Operating Revenues: Time charter $ 41,850 $ 87,729 $ 66,407 $ 55,399 $ 251,385 Bareboat charter — — — 1,460 1,460 Other marine services 17,678 2,582 4,345 2,061 26,666 59,528 90,311 70,752 58,920 279,511 Direct Costs and Expenses: Operating: Personnel 26,110 20,434 20,786 14,440 81,770 Repairs and maintenance 5,146 9,624 7,109 4,947 26,826 Drydocking 2,314 2,946 ( 99 ) 1,437 6,598 Insurance and loss reserves 3,752 1,727 3,638 839 9,956 Fuel, lubes and supplies 3,697 6,830 3,552 3,108 17,187 Other 1,427 10,072 3,961 1,853 17,313 42,446 51,633 38,947 26,624 159,650 Direct Vessel Profit $ 17,082 $ 38,678 $ 31,805 $ 32,296 $ 119,861 Other Costs and Expenses: Lease expense $ 536 $ 1,498 $ 360 $ 354 2,748 Administrative and general 49,183 Depreciation and amortization 14,685 15,346 14,760 9,030 53,821 105,752 Gains on asset dispositions and impairments, net 21,409 Operating income $ 35,518 As of December 31, 2023 Property and Equipment: Historical cost $ 209,262 $ 272,272 $ 267,079 $ 170,210 $ 918,823 Accumulated depreciation ( 99,137 ) ( 93,045 ) ( 94,708 ) ( 37,251 ) ( 324,141 ) $ 110,125 $ 179,227 $ 172,371 $ 132,959 $ 594,682 Total Assets (1) $ 142,264 $ 215,158 $ 199,174 $ 152,427 $ 709,023 (1) Total Assets exclude $ 71.3 million of corporate assets. United States Africa and Europe Middle East Latin America Total For the year ended December 31, 2022 Operating Revenues: Time charter $ 51,272 $ 60,060 $ 52,080 $ 40,122 $ 203,534 Bareboat charter — — — 1,374 1,374 Other marine services 9,528 ( 163 ) 762 2,290 12,417 60,800 59,897 52,842 43,786 217,325 Direct Costs and Expenses: Operating: Personnel 25,201 16,436 22,376 13,769 77,782 Repairs and maintenance 7,049 9,229 8,111 7,107 31,496 Drydocking 8,978 2,339 6,569 274 18,160 Insurance and loss reserves 4,831 1,178 2,838 1,115 9,962 Fuel, lubes and supplies 3,345 8,022 5,089 2,833 19,289 Other 1,235 7,175 4,633 2,253 15,296 50,639 44,379 49,616 27,351 171,985 Direct Vessel Profit $ 10,161 $ 15,518 $ 3,226 $ 16,435 $ 45,340 Other Costs and Expenses: Lease expense $ 998 $ 1,691 $ 156 $ 1,024 3,869 Administrative and general 40,911 Depreciation and amortization 17,444 13,708 16,331 8,474 55,957 100,737 Gains on asset dispositions and impairments, net 1,398 Operating loss $ ( 53,999 ) As of December 31, 2022 Property and Equipment: Historical cost $ 232,740 $ 285,303 $ 286,745 $ 162,895 $ 967,683 Accumulated depreciation ( 101,503 ) ( 92,030 ) ( 89,444 ) ( 27,801 ) ( 310,778 ) $ 131,237 $ 193,273 $ 197,301 $ 135,094 $ 656,905 Total Assets (1) $ 174,081 $ 211,371 $ 215,497 $ 150,650 $ 751,599 (1) Total Assets exclude $ 64.0 million of corporate assets. United States Africa and Europe, Continuing Operations Middle East Latin America Total For the year ended December 31, 2021 Operating Revenues: Time charter $ 15,487 $ 44,268 $ 53,146 $ 46,934 $ 159,835 Bareboat charter 1,549 — — 2,484 4,033 Other marine services 3,607 ( 1,338 ) 526 4,278 7,073 20,643 42,930 53,672 53,696 170,941 Direct Costs and Expenses: Operating: Personnel 8,836 13,903 22,191 14,990 59,920 Repairs and maintenance 3,394 6,772 6,701 7,250 24,117 Drydocking 2,082 1,159 2,639 467 6,347 Insurance and loss reserves 2,632 1,353 2,481 2,201 8,667 Fuel, lubes and supplies 1,204 4,109 3,459 3,261 12,033 Other 648 5,815 6,158 3,701 16,322 18,796 33,111 43,629 31,870 127,406 Direct Vessel Profit $ 1,847 $ 9,819 $ 10,043 $ 21,826 $ 43,535 Other Costs and Expenses: Lease expense $ 2,621 $ 1,281 $ 472 $ 1,711 6,085 Administrative and general 37,639 Depreciation and amortization 15,712 12,856 17,985 10,842 57,395 101,119 Gains on asset dispositions and impairments, net 20,436 Operating loss $ ( 37,148 ) As of December 31, 2021 Property and Equipment: Historical cost $ 240,717 $ 218,544 $ 340,225 $ 208,594 $ 1,008,080 Accumulated depreciation ( 115,088 ) ( 69,310 ) ( 85,683 ) ( 32,247 ) ( 302,328 ) $ 125,629 $ 149,234 $ 254,543 $ 176,347 $ 705,752 Total Assets (1) $ 148,753 $ 167,185 $ 256,533 $ 250,594 $ 823,065 (1) Total Assets exclude $ 89.4 million of corporate assets.

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2023
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Assets Held for Sale	Summarized selected operating results of the Company’s assets held for sale and discontinued operations were as follows for the years ended December 31, (in thousands): 2020 Assets from Discontinued Operations: Current assets $ 10,138 Net property and equipment 34,580 Non-current assets 5,517 50,235 Liability from Discontinued Operations: Current liabilities 2,418 Long-term liabilities 28,509 $ 30,927 Windcat Workboats 2021 Operating Revenues: Time charter $ 903 Other revenue 70 973 Costs and Expenses: Operating 578 Direct Vessel Profit 395 General and Administrative Expenses 238 Lease Expense 24 Depreciation — Operating Income 133 Other Income (Expense) Interest income 2 Interest expense ( 39 ) Foreign currency translation gain (loss) 89 Other, net — 52 Operating Income Before Equity Earnings of 50% or 185 Income Tax Benefit — Operating Income Before Equity Earnings of 50% or 185 Equity in (Losses) Earnings of 50% or Less Owned Companies, ( 16 ) Net Income from Discontinued Operations $ 169

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Tables)	12 Months Ended
	Dec. 31, 2023
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule of Valuation and Qualifying Accounts	(in thousands) Description Balance Reserves Acquired Charges Deductions Balance Year Ended December 31, 2023 Allowance for credit loss reserves (deducted from trade and notes receivable) $ 1,650 $ — $ 3,519 $ ( 626 ) $ 4,543 Year Ended December 31, 2022 Allowance for credit loss reserves (deducted from trade and notes receivable) $ 1,312 $ — $ 489 $ ( 151 ) $ 1,650 Year Ended December 31, 2021 Allowance for credit loss reserves (deducted from trade and notes receivable) $ 582 $ 3 $ 863 $ ( 136 ) $ 1,312

Nature of Operations and Acco_4

Nature of Operations and Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) Vessel Segment $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Oct. 05, 2022 $ / shares	Dec. 31, 2020 USD ($)
Nature Of Operations And Accounting Policies [Line Items]
Number of reportable segments | Segment	4
Unearned revenue	$ 687,000	$ 2,333,000	$ 1,606,000		$ 4,452,000
Inventory reserves	0	0	0
Net book value	594,682,000	656,905,000	705,752,000
Capitalized interest costs, including allowance for funds used during construction, total	0	0	300,000
Impairment of long-lived assets held-for-use		$ 2,900,000
Impairment, Long-Lived Asset, Held-for-Use, Statement of Income or Comprehensive Income [Extensible Enumeration]		Gain (Loss) on Sale of Assets and Asset Impairment Charges
Assets held for sale	500,000	$ 6,750,000
Equity method investment, other than temporary impairment	$ 0	$ 0	$ 0
Class of warrant or right, exercise price of warrants or rights | $ / shares	$ 0.01			$ 0.01
Earnings (loss) per share | $ / shares	$ (0.34)	$ (2.69)	$ 1.30
Operating Revenues
Nature Of Operations And Accounting Policies [Line Items]
Business interruption insurance recoveries	$ 6,500,000
Performance Share Awards
Nature Of Operations And Accounting Policies [Line Items]
Number of shares issued | shares	156,620	184,930	157,455
Number of shares outstanding | shares	156,620	216,172	354,964
Fast Support Vessel
Nature Of Operations And Accounting Policies [Line Items]
Impairment charges		$ 900,000
Anchor Handling Towing Supply
Nature Of Operations And Accounting Policies [Line Items]
Impairment of long-lived assets held-for-use	$ 700,000	700,000
Tower and Gangway
Nature Of Operations And Accounting Policies [Line Items]
Impairment charges		$ 1,300,000
Restricted Stock
Nature Of Operations And Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount | shares	1,642,084	1,682,193	1,112,256
Dilutive securities included in computation of earnings per share, amount | shares			50,834
Employee Stock Option
Nature Of Operations And Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount | shares	1,026,031	1,026,865	1,061,357
Convertible Debt Securities
Nature Of Operations And Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount | shares	2,978,274	2,978,274	2,907,500
Continuing Operations
Nature Of Operations And Accounting Policies [Line Items]
Depreciation, total	$ 53,800,000	$ 56,000,000	$ 57,400,000
Discontinued Operations
Nature Of Operations And Accounting Policies [Line Items]
Depreciation, total	$ 0	0	0
Offshore Support Vessels
Nature Of Operations And Accounting Policies [Line Items]
Estimated useful life (Year)	20 years
OVH
Nature Of Operations And Accounting Policies [Line Items]
Equity method investment, ownership percentage	49%
SEACOR Marlin LLC
Nature Of Operations And Accounting Policies [Line Items]
Equity method investment, ownership percentage	49%
Earnings (loss) per share | $ / shares	$ 0.01
Equity Investments in 50% or Less Owned Companies | Minimum
Nature Of Operations And Accounting Policies [Line Items]
Equity method investment, ownership percentage	20%
Equity Investments in 50% or Less Owned Companies | Minimum | SEACOR Marine Foreign Holdings
Nature Of Operations And Accounting Policies [Line Items]
Equity method investment, ownership percentage	50%
Equity Investments in 50% or Less Owned Companies | Maximum
Nature Of Operations And Accounting Policies [Line Items]
Equity method investment, ownership percentage	50%
UNITED STATES
Nature Of Operations And Accounting Policies [Line Items]
Number of vessels | Vessel	13
Number of vessels owned | Vessel	11
Number of vessels managed-in | Vessel	2
Net book value	$ 110,125,000	131,237,000	125,629,000
Africa and Europe
Nature Of Operations And Accounting Policies [Line Items]
Number of vessels | Vessel	19
Number of vessels owned | Vessel	18
Number of vessels leased-in | Vessel	1
Net book value	$ 179,227,000	193,273,000	149,234,000
Assets held for sale	$ 500,000
Middle East and Asia
Nature Of Operations And Accounting Policies [Line Items]
Number of vessels | Vessel	16
Number of vessels owned | Vessel	15
Number of vessels managed-in | Vessel	1
Net book value	$ 172,371,000	197,301,000	254,543,000
Latin America
Nature Of Operations And Accounting Policies [Line Items]
Number of vessels owned | Vessel	10
Net book value	$ 132,959,000	$ 135,094,000	$ 176,347,000

Nature of Operations and Acco_5

Nature of Operations and Accounting Policies - Schedule Of Deferred Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Nature Of Operation And Accounting Policies [Abstract]
Balance at beginning of year	$ 2,333	$ 1,606	$ 4,452
Unearned revenues during the year	6,501	4,288	10,167
Revenues recognized during the year	(8,147)	(3,561)	(13,013)
Balance at end of year	$ 687	$ 2,333	$ 1,606

Nature of Operations and Acco_6

Nature of Operations and Accounting Policies - Schedule Of Cash, Cash Equivalents And Restricted Cash From Continuing Operations (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Nature Of Operation And Accounting Policies [Abstract]
Cash	$ 67,455	$ 39,963
Restricted cash	16,676	3,082
Total	$ 84,131	$ 43,045

Nature of Operations and Acco_7

Nature of Operations and Accounting Policies - Summary of Property and Equipment from Continuing Operations (Details) - USD ($) $ in Thousands		Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021
Historical cost		$ 918,823	[1]	$ 967,683	[1]	$ 1,008,080
Accumulated depreciation		(324,141)		(310,778)		(302,328)
Net book value		594,682		656,905		$ 705,752
Offshore Support Vessels, Anchor Handling Towing Supply
Historical cost	[1],[2]	12,112		27,281
Accumulated depreciation	[2]	(4,578)		(18,139)
Net book value	[2]	7,534		9,142
Fast Support Vessels
Historical cost	[1],[3]	340,411		354,473
Accumulated depreciation	[3]	(142,096)		(130,599)
Net book value	[3]	198,315		223,874
Platform Supply Vessels
Historical cost	[1],[4]	301,461		295,875
Accumulated depreciation	[4]	(53,100)		(36,112)
Net book value	[4]	248,361		259,763
Offshore Support Vessels, Specialty
Historical cost	[1]			3,163
Accumulated depreciation				(3,138)
Net book value				25
Offshore Support Vessels, Liftboats
Historical cost	[1]	243,295		264,142
Accumulated depreciation		(103,459)		(102,156)
Net book value		139,836		161,986
General Machinery and Spares
Historical cost	[1]	9,343		10,148
Accumulated depreciation		(9,161)		(8,565)
Net book value		182		1,583
Property, Plant and Equipment, Other Types
Historical cost	[1],[5]	12,201		12,601
Accumulated depreciation	[5]	(11,747)		(12,069)
Net book value	[5]	$ 454		$ 532
[1] Includes property and equipment acquired in business acquisitions at acquisition date fair value and net of the impact of recognized impairment charges. Some of the Company’s vessels are pledged as security for certain loans. Anchor Handling Towing Supply vessels (“AHTS”). Fast support vessels (“FSVs”). Platform support vessels (“PSVs”). Includes buildings, leasehold improvements, vehicles and other property and equipment.

Nature of Operations and Acco_8

Nature of Operations and Accounting Policies - Schedule of Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	$ 379,146	$ 446,541	$ 401,836
Other comprehensive income (loss)	730	(1,208)	5,265
Income tax expense	0	0	0
Balance	374,224	379,146	446,541
Accumulated Foreign Currency Adjustment Attributable to Parent
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	6,332	10,783	6,797
Other comprehensive income (loss)	1,245	(4,451)	3,986
Income tax expense	0	0	0
Balance	7,577	6,332	10,783
Accumulated (Losses) Gains, Net, Cash Flow Hedge, Parent
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(515)	(2,728)	(4,007)
Other comprehensive income (loss)	(515)	3,243	1,279
Income tax expense	0	0	0
Balance	0	(515)	(2,728)
AOCI Attributable to Parent
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	6,847	8,055	2,790
Other comprehensive income (loss)	730	(1,208)	5,265
Income tax expense	0	0	0
Balance	7,577	6,847	8,055
Accumulated Foreign Currency Adjustment Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(1,445)	(1,445)	(1,445)
Other comprehensive income (loss)	0	0	0
Income tax expense	0	0	0
Balance	(1,445)	(1,445)	(1,445)
Accumulated Loss, Net, Cash Flow Hedge, Noncontrolling Interest
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(11)	(11)	(11)
Other comprehensive income (loss)	0	0	0
Income tax expense	0	0	0
Balance	(11)	(11)	(11)
AOCI Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(1,208)	5,265	1,242
Other comprehensive income (loss)	730	(1,208)	5,265
Income tax expense	0	0	0
Balance	$ (730)	$ (1,208)	$ 5,265

Business Acquisitions - Additio

Business Acquisitions - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021 shares
OSV Partners | Merger Agreement | Common Stock [Member] | Merger Consideration
Business Acquisition [Line Items]
Common stock issued	1,567,935

Business Acquisitions - Summary

Business Acquisitions - Summary of Purchase Price Allocation of Acquired Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Schedule Of Investments [Line Items]
Equity Investment	$ (4,125)	$ (3,024)

Note Receivable - Additional In

Note Receivable - Additional Information (Details) - USD ($)		12 Months Ended
	Sep. 29, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounts Notes And Loans Receivable [Line Items]
Prepayment of outstanding loan		$ 1,827,000	$ 2,271,000	$ 755,000
MexMar Original Facility Agreement
Accounts Notes And Loans Receivable [Line Items]
Outstanding principal of loan	$ 28,800,000
MexMar Original Facility Agreement | Term Loan
Accounts Notes And Loans Receivable [Line Items]
Outstanding principal of loan	28,800,000
MexMar Third A&R Facility Agreement
Accounts Notes And Loans Receivable [Line Items]
Outstanding principal of loan	20,000,000
Prepayment of outstanding loan	$ 8,800,000
Debt instrument, maturity date	Sep. 30, 2023
Frequency of principal repayment		four quarterly installments
Principal repayment of loan	$ 5,000,000
MexMar Third A&R Facility Agreement | Term Loan
Accounts Notes And Loans Receivable [Line Items]
Outstanding principal of loan	20,000,000
Prepayment of outstanding loan	$ 8,800,000
Debt instrument, maturity date	Sep. 30, 2023
Frequency of principal repayment	four quarterly installments
Principal repayment of loan	$ 5,000,000

Equipment Acquisitions and Di_3

Equipment Acquisitions and Dispositions - Additional Information (Details)		12 Months Ended
	Jan. 12, 2021 USD ($)	Dec. 31, 2023 USD ($) Vessel	Dec. 31, 2022 USD ($) Vessel	Dec. 31, 2021 USD ($) Vessel
Property Plant And Equipment [Line Items]
Capital expenditures and payments on equipment		$ 10,600,000	$ 500,000	$ 7,000,000
Gain (loss) on disposition of property, plant and equipment	$ 22,756
Proceeds from sale of business	38,715	44,730,000	6,734,000	30,137,000
Property plant equipment consideration transferred				30,100,000
Proceeds from disposition of property and equipment	$ 38,715	$ 44,730,000	$ 6,734,000	30,137,000
Falcon Global U S A Term Loan Facility
Property Plant And Equipment [Line Items]
Reduced of debt under credit facility				$ 22,500,000
Specialty Vessel
Property Plant And Equipment [Line Items]
Number of equipment sold | Vessel		1
Fast Support Vessels
Property Plant And Equipment [Line Items]
Number of equipment sold | Vessel		1	1	3
Impairment charges			$ 900,000
Platform Supply Vessels
Property Plant And Equipment [Line Items]
Number of equipment sold | Vessel				1
Proceeds from sale of business		$ 44,700,000	6,700,000
Proceeds from disposition of property and equipment		44,700,000	6,700,000
Platform Supply Vessels And Fast Support Vessels
Property Plant And Equipment [Line Items]
Gain (loss) on disposition of property, plant and equipment		$ 21,100,000	$ 2,200,000	$ 20,900,000
Proceeds from sale of business				25,000,000
Proceeds from disposition of property and equipment				$ 25,000,000
Liftboats
Property Plant And Equipment [Line Items]
Number of equipment sold, classified as held for sale | Vessel		1
Number of equipment sold | Vessel		3	1
Maximum | Equity Investments in 50% or Less Owned Companies
Property Plant And Equipment [Line Items]
Equity method investment, ownership percentage		50%

Equipment Acquisitions and Di_4

Equipment Acquisitions and Dispositions - Schedule of Vessel Acquired and Disposed (Details)		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022		Dec. 31, 2021
Property Plant And Equipment [Line Items]
Acquired		1	1		1	[1]
Removed from service		6	3	[2]	5	[3]
Anchor Handling Towing Supply
Property Plant And Equipment [Line Items]
Removed from service	[2]		1
Fast Support Vessels
Property Plant And Equipment [Line Items]
Acquired		1
Removed from service		1	1	[2]	3	[3]
Platform Supply Vessels
Property Plant And Equipment [Line Items]
Acquired			1		1	[1]
Removed from service	[3]				1
Offshore Support Vessels, Liftboats
Property Plant And Equipment [Line Items]
Removed from service		4	1	[2]	1	[3]
Specialty Vessel
Property Plant And Equipment [Line Items]
Removed from service		1
[1] Excludes five PSVs acquired as part of the OSV Partners Acquisition in 2021. Excludes one specialty vessel that was previously removed from service, which was sold in 2023. Excludes four liftboats that were previously removed from service, of which three were sold in 2023 and one was sold in 2022. On January 12, 2021, a wholly owned subsidiary of the Company, completed the sale of the Company’s Windcat Workboats crew transfer vessel (“CTV”) business through the sale of 100% of the equity of Windcat Workboats, a wholly owned subsidiary of the Company (“Windcat” and together with its subsidiaries, the “Windcat Group”), to CMB N.V. (the “Windcat Buyer”) pursuant to a Sale and Purchase Agreement entered into on December 18, 2020. At closing, the Windcat Buyer paid to the Company an aggregate purchase price of £32.8 million. After deducting transaction costs and expenses and giving effect to foreign exchange rate hedges, the Company received net cash proceeds of approximately $42.6 million. The Windcat Buyer also assumed all of the approximately £20.4 million of debt outstanding under Windcat Workboat’s existing revolving credit facility. As of December 31, 2020, the Windcat Group owned a total of 41 CTVs and held interests in an additional five CTVs through its joint ventures, all of which were included in the sale. The Company recognized a gain on the sale of Windcat Workboats of approximately $22.8 million during 2021, calculated as follows: (In Thousands): January 12, 2021 Total Proceeds Received $ 43,797 Transactions Fees and other Costs 1,562 Cash Sold 3,520 Total Net Proceeds 38,715 Less: Net Equity in Windcat Workboats, net of cash sold 15,790 Less: January Income on Discontinued Operations 169 Gain on Sale of Windcat Workboats $ 22,756

Equipment Acquisitions and Di_5

Equipment Acquisitions and Dispositions - Schedule of Vessel Acquired and Disposed (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2023 Vessel	Dec. 31, 2022 Vessel	Dec. 31, 2021 Vessel
Platform Supply Vessels
Property Plant And Equipment [Line Items]
Number of equipment acquired excludes from deliveries of offshore support vessels			5
Number of equipment sold			1
Offshore Support Vessels, Liftboats
Property Plant And Equipment [Line Items]
Number of Equipment Removed from Service Excludes from Major Equipment Dispositions			4
Number of equipment sold	3	1
Specialty Vessel
Property Plant And Equipment [Line Items]
Number of Equipment Removed from Service Excludes from Major Equipment Dispositions		1
Number of equipment sold	1

Equipment Acquisitions and Di_6

Equipment Acquisitions and Dispositions - Schedule of Gain on Sale of Windcat Workboats (Details) - USD ($)			12 Months Ended
	Sep. 29, 2022	Jan. 12, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Total Proceeds Received		$ 43,797
Transactions Fees and other Costs	$ 1,159,000	1,562
Cash Sold		3,520
Total Net Proceeds		38,715	$ 44,730,000	$ 6,734,000	$ 30,137,000
Less: Net Equity in Windcat Workboats, net of cash sold		15,790
Less: January Income on Discontinued Operations		169
Gain on Sale of Windcat Workboats		$ 22,756

Investments, at Equity, and A_3

Investments, at Equity, and Advances to 50% or Less Owned Companies - Schedule of Equity Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule Of Investments [Line Items]
Investments at equity	$ 4,125	$ 3,024
Current assets	164,686	132,313
Current liabilities	77,086	121,162
Operating Revenues	279,511	217,325	$ 170,941
Operating (Loss) Income	(9,314)	(71,649)	33,137
Net (Loss) Income	$ (9,314)	(71,649)	33,137
SEACOR Marlin LLC
Schedule Of Investments [Line Items]
Ownership percentage	49%
Seabulk Angola
Schedule Of Investments [Line Items]
Ownership percentage	49%
Investments at equity	$ 1,668	1,683
SEACOR Marine Arabia
Schedule Of Investments [Line Items]
Ownership percentage	45%
Investments at equity	$ 2,385	1,265
Other Offshore Marine Services Joint Ventures
Schedule Of Investments [Line Items]
Investments at equity	$ 72	76
Other Offshore Marine Services Joint Ventures | Minimum
Schedule Of Investments [Line Items]
Ownership percentage	20%
Other Offshore Marine Services Joint Ventures | Maximum
Schedule Of Investments [Line Items]
Ownership percentage	50%
All Other Excluding MexMar, Falcon Global, Sea-Cat Crewzer and Sea-Cat Crewzer II
Schedule Of Investments [Line Items]
Current assets	$ 29,820	24,699
Noncurrent assets	61	266
Current liabilities	21,008	17,070
Noncurrent liabilities	0	0
Operating Revenues	68,949	133,740	156,579
Operating and administrative	61,294	90,678	139,313
Depreciation	27	21,434	23,524
Costs and expenses	61,321	112,112	162,837
Operating (Loss) Income	7,628	21,628	(6,258)
Net (Loss) Income	$ 5,239	$ 15,057	$ 41,798

Investments, at Equity, and A_4

Investments, at Equity, and Advances to 50% or Less Owned Companies - Additional Information (Details)

12 Months Ended

Sep. 29, 2022 USD ($)

Dec. 10, 2021 USD ($)

Dec. 09, 2021 USD ($)

Jul. 23, 2021 USD ($) Vessel

Jun. 01, 2021 USD ($) Vessel

Dec. 28, 2018 USD ($)

Dec. 20, 2018 USD ($)

Sep. 13, 2018 USD ($)

Dec. 31, 2023 USD ($)

Dec. 31, 2022 USD ($) Vessel

Dec. 31, 2021 USD ($)

Dec. 31, 2019 USD ($) Equipment

Dec. 31, 2018 USD ($)

Dec. 31, 2017 USD ($)

Schedule Of Investments [Line Items]

Consolidated retained earnings

$ 2,800,000

Capital distributions from equity investees

0

$ 0

$ 9,442,000

Vessel management fees

$ 600,000

$ 600,000

Proceeds from divestiture of interest in joint venture

$ 7,000,000

Proceeds from sale of investment in equity investees

66,000,000

$ 0

66,000,000

0

Gain on sale recognized, amount

$ 788,000

Subsidiaries of CME

Schedule Of Investments [Line Items]

Noncontrolling interest, ownership percentage by noncontrolling owners

51%

Prior to the Closing of the Framework Agreement Transactions | OTM

Schedule Of Investments [Line Items]

Noncontrolling interest, ownership percentage by noncontrolling owners

51%

MexMar

Schedule Of Investments [Line Items]

Capital distributions from equity investees

0

0

MexMar | Related Party

Schedule Of Investments [Line Items]

Vessel management fees

$ 200,000

300,000

MexMar | Prior to the Closing of the Framework Agreement Transactions

Schedule Of Investments [Line Items]

Equity method investment, ownership percentage

49%

MexMar | Offshore Support Vessels

Schedule Of Investments [Line Items]

Number of equipment operated | Vessel

19

SEACOR Marlin LLC

Schedule Of Investments [Line Items]

Capital distributions from equity investees

$ 1,100,000

2,500,000

Equity method investment, ownership, percent sold

51%

Proceeds from divestiture of interest in joint venture

$ 8,000,000

Gain (loss) on disposition of business

$ 400,000

Equity method investment, ownership percentage

49%

SEACOR Marine Arabia and other

Schedule Of Investments [Line Items]

Capital distributions from equity investees

$ 2,200,000

2,000,000

2,000,000

SEACOR Marine Arabia and other | Related Party

Schedule Of Investments [Line Items]

Vessel management fees

$ 0

0

0

Mexmar Offshore International

Schedule Of Investments [Line Items]

Equity method investment, ownership percentage

50%

50%

Mexmar Offshore International | Subsidiaries of CME

Schedule Of Investments [Line Items]

Equity method investment, ownership percentage

49%

Noncontrolling interest, ownership percentage by noncontrolling owners

51%

51%

Mexmar Offshore International | UP Offshore

Schedule Of Investments [Line Items]

Purchase price

$ 30,200,000

Percentage of gain from equity earnings

50%

Gain on equity earnings

$ 2,600,000

Mexmar Offshore International | Offshore Support Vessels, Supply

Schedule Of Investments [Line Items]

Number of vessels sold | Vessel

8

MEXMAR Offshore

Schedule Of Investments [Line Items]

Gain on equity earnings

$ 2,600,000

Received distribution from joint ventures

12,000,000

Aggregate purchase price

$ 9,400,000

Number of vessels owned | Vessel

3

Number of vessels joint ventured | Vessel

2

Transferred equity interest

49%

Equity interest transferred consideration and transaction fee.

$ 200,000

Contributed capital

$ 5,000,000

Offshore Vessel Holdings

Schedule Of Investments [Line Items]

Payments to acquire interest in joint venture

$ 4,900,000

Contributed capital

$ 10,000,000

Financing agreement

$ 2,400,000

Management fees

$ 0

$ 1,000,000

Offshore Vessel Holdings | Subsidiaries of CME

Schedule Of Investments [Line Items]

Noncontrolling interest, ownership percentage by noncontrolling owners

51%

Offshore Vessel Holdings | Subsidiaries Of OVH

Schedule Of Investments [Line Items]

Noncontrolling Interest, ownership percentage by parent

49%

Offshore Vessel Holdings | Offshore Support Vessels, Supply

Schedule Of Investments [Line Items]

Number of equipment operated | Equipment

3

Offshore Vessel Holdings | Jack up Drillings [Member]

Schedule Of Investments [Line Items]

Number of equipment operated | Equipment

2

Offshore Vessel Holdings | F S V Offshore Support Vessels

Schedule Of Investments [Line Items]

Number of equipment operated | Equipment

1

OVH and OPEM

Schedule Of Investments [Line Items]

Settled loan

$ 10,000,000

Early repayment of debt

10,500,000

Forgiveness of accrued interest

$ 4,100,000

Investments, at Equity, and A_5

Investments, at Equity, and Advances to 50% or Less Owned Companies - Schedule of Gain on Sale of Equity Investments (Details) - USD ($)			12 Months Ended
	Sep. 29, 2022	Jan. 12, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule of Investments [Abstract]
Proceeds from sale of investment in equity investees	$ 66,000,000		$ 0	$ 66,000,000	$ 0
51% ownership in SEACOR Marlin Joint Venture	7,000,000
Hybrid Battery Power System	1,394,000
Transactions Fees and other Costs	1,159,000	$ 1,562
Total Net Proceeds	73,235,000
Less: Net Equity in MexMar and OVH Joint Ventures	65,546,000
Less: Net Book Value of SEACOR Davis	5,507,000
Less: OVH Note Receivable	1,394,000
Gain on Sale of MexMar, OVH and Other Assets	$ 788,000

Leases - Additional Information

Leases - Additional Information (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) Vessel	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Lessee Lease Description [Line Items]
Operating lease, impairment loss | $	$ 700,000	$ 700,000	$ 0
Anchor Handling Towing Supply
Lessee Lease Description [Line Items]
Number of operating leases on equipment | Vessel	1
Vessels
Lessee Lease Description [Line Items]
Operating and finance lease, lease terms (in duration)	9 months
Other Equipment | Minimum
Lessee Lease Description [Line Items]
Operating lease, lease terms (in duration)	2 months
Other Equipment | Maximum
Lessee Lease Description [Line Items]
Operating lease, lease terms (in duration)	276 months
Machinery and Equipment | Maximum
Lessee Lease Description [Line Items]
Operating lease, lease terms (in duration)	12 months

Leases - Summary of Future Mini

Leases - Summary of Future Minimum Payments For Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Operating Leases
2024	$ 1,864
2025	746
2026	459
2027	400
2028	341
Years subsequent to 2028	2,873
Operating lease payments due	6,683
Interest component	(1,563)
Total operating leases	5,120
Current portion of operating lease liabilities	1,591	$ 2,358
Long-term operating lease liabilities	3,529	4,739
Finance Leases
2024	36
2025	6
2026	0
2027	0
2028	0
Years subsequent to 2028	0
Total finance leases	42
Interest component	(1)
Finance Leases	41
Current portion of finance lease liabilities	35	468
Long-term finance lease liabilities	$ 6	$ 6,781

Leases - Summary of Components

Leases - Summary of Components of Leases Expense (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating lease cost		$ 2,222	$ 3,162
Finance lease cost:
Amortization of finance lease asset	[1]	468	545
Interest on lease liabilities	[2]	202	246
Short-term lease costs		526	707
Total lease expense		$ 3,418	$ 4,660
[1] Included in amortization costs in the consolidated statements of income (loss). Included in interest expense in the consolidated statements of income (loss).

Leases - Summary of Supplementa

Leases - Summary of Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating cash flows from operating leases	$ 2,362
Financing cash outflows from finance leases	531	$ 351	$ 30
Right-of-use assets obtained for operating lease liabilities	499
Right-of-use assets obtained for finance lease liabilities	$ 0

Leases - Summary of Other Infor

Leases - Summary of Other Information Related to Leases (Details)	Dec. 31, 2023
Leases [Abstract]
Weighted average remaining lease term, in years - operating leases	10 years 2 months 12 days
Weighted average remaining lease term, in years - finance leases	1 year 2 months 12 days
Weighted average discount rate - operating leases	6.70%
Weighted average discount - finance leases	4%

Long Term Debt - Schedule of Lo

Long Term Debt - Schedule of Long-term Debt Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 353,024	$ 363,794
Current portion due within one year	(28,365)	(61,512)
Unamortized debt discount	(32,885)	(37,511)
Deferred financing costs	(4,230)	(4,652)
Long-term debt, less current portion	287,544	260,119
Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	353,024	358,294
Non-Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	0	5,500
Guaranteed Notes | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	90,000	90,000
New Convertible Notes
Debt Instrument [Line Items]
Unamortized debt discount	(3,700)	(4,900)
New Convertible Notes | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	35,000	35,000
2023 SMFH Credit Facility | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	118,950	0
2018 SMFH Credit Facility | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	0	67,910
Sea-Cat Crewzer III Term Loan Facility | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	14,227	16,703
SEACOR Delta Shipyard Financing | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	68,647	77,537
SEACOR Alpine Credit Facility | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	26,200	0
SEACOR Alpine Shipyard Financing | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	0	27,790
SEACOSCO Acquisition Debt | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	0	16,205
SEACOR 88/888 Term Loan | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	0	5,500
SEACOR 88/888 Term Loan | Non-Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	0	5,500
Tarahumara Shipyard Financing | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	0	5,597
SEACOR Offshore OSV | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 0	$ 16,052

Long Term Debt - Schedule of _2

Long Term Debt - Schedule of Long-term Debt Obligations (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2023 Vessel	Dec. 31, 2022	Dec. 31, 2021	[1]
Debt Instrument [Line Items]
Number of vessels acquired	1	1	1
SEACOR Delta Shipyard Financing | SEACOSCO Offshore LLC
Debt Instrument [Line Items]
Number of vessels acquired	8
[1] Excludes five PSVs acquired as part of the OSV Partners Acquisition in 2021.

Long Term Debt - Schedule of _3

Long Term Debt - Schedule of Long-term Debt Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
2024	$ 28,365
2025	28,605
2026	152,405
2027	27,165
2028	110,257
Years subsequent to 2028	6,227
Long-term Debt, Gross	$ 353,024	$ 363,794

Long Term Debt - Additional Inf

Long Term Debt - Additional Information (Details) $ / shares in Units, € in Millions

12 Months Ended

Sep. 08, 2023 USD ($)

Jun. 16, 2023 USD ($) Installments

Dec. 22, 2022 USD ($)

Oct. 05, 2022 USD ($) $ / shares

Sep. 29, 2022 USD ($)

Aug. 02, 2022 USD ($)

Jul. 23, 2021 USD ($)

Jun. 29, 2021 USD ($)

Jun. 24, 2021 USD ($)

Jun. 18, 2021 USD ($)

Jun. 10, 2021 USD ($) Liftboat

Sep. 26, 2018 USD ($)

May 02, 2018 USD ($) $ / shares shares

Dec. 01, 2015 USD ($) $ / shares

Dec. 31, 2023 USD ($) Vessel $ / shares

Dec. 31, 2022 USD ($)

Dec. 31, 2021 USD ($) Vessel $ / shares

Dec. 31, 2019 Vessel

Dec. 31, 2018 USD ($)

Dec. 31, 2017 USD ($)

Dec. 31, 2016 USD ($)

Feb. 25, 2021 USD ($)

Jun. 30, 2020 USD ($)

May 31, 2020 USD ($)

Dec. 20, 2018 USD ($)

Jul. 05, 2018 USD ($)

Apr. 21, 2016 EUR (€)

Debt Instrument [Line Items]

Number of vessels acquired

1

1

1

[1]

Repayments of long-term debt, total

$ 29,165,000

$ 38,152,000

$ 78,124,000

Gain on troubled debt restructuring, increase of basic earnings per share | $ / shares

$ 2.44

Gain on troubled debt restructuring, increase of diluted earnings per share | $ / shares

$ 2.43

Payments on debt extinguishment costs

(1,827,000)

(2,271,000)

$ (755,000)

Cash and Cash Equivalents

$ 84,131,000

43,045,000

Class of warrant or right, exercise price of warrants or rights | $ / shares

$ 0.01

$ 0.01

Letters of credit outstanding, amount

$ 1,100,000

Indebtedness

$ 95,000,000

Unamortized discount

$ 32,885,000

37,511,000

Amortization of debt discount and issue costs

4,000,000

Contractual interest expense

4,000,000

Total interest expense

$ 8,000,000

Conditional Payoff Agreement

Debt Instrument [Line Items]

Repayments of long-term debt, total

$ 50,000,000

Reimbursement amount

$ 2,500,000

Number of lift boats released from mortgages and security arrangements | Liftboat

9

Gain on restructuring of debt

$ 62,000,000

Redeemed Prior to October 1, 2023 | Conditional Payoff Agreement

Debt Instrument [Line Items]

Repayments of long-term debt, total

25,000,000

Redeemed On or After October 1, 2024 | Conditional Payoff Agreement

Debt Instrument [Line Items]

Repayments of long-term debt, total

$ 2,500,000

Redeemed On or After October 1, 2023 but Prior to October 1, 2024 | Conditional Payoff Agreement

Debt Instrument [Line Items]

Repayments of long-term debt, total

$ 22,500,000

SEACOR Offshore OSV

Debt Instrument [Line Items]

Line of credit facility assumed and guaranteed

$ 18,100,000

Number of vessels acquired | Vessel

5

SEACOR Offshore OSV | Tranche A

Debt Instrument [Line Items]

Credit facility quarterly principal payments

$ 330,450

$ 500,000

Credit facility, interest rate

4.75%

4.68%

Credit facility, maturity date

Mar. 31, 2026

Dec. 31, 2023

Debt instrument, face amount

$ 10,900,000

SEACOR Offshore OSV | Tranche B

Debt Instrument [Line Items]

Debt instrument, face amount

$ 5,600,000

Term and Revolving Loan Facility | Conditional Payoff Agreement

Debt Instrument [Line Items]

Line of credit facility, outstanding amount

$ 117,300,000

SEACOR Alpine Shipyard Financing

Debt Instrument [Line Items]

Number of vessels acquired | Vessel

3

Debt instrument, interest rate

5%

Percentage of amount of loan financed

70%

Debt instrument, term of delivery

4 years

Senior Secured Term Loan with EnTrust Global

Debt Instrument [Line Items]

Line of credit facility, maximum borrowing capacity

$ 122,000,000

Loan Facility With DNB Bank ASA

Debt Instrument [Line Items]

Line of credit facility, maximum borrowing capacity

$ 130,000,000

Principal repayment of loan

3,300,000

SEACOR Marine Foreign Holdings Credit Facility

Debt Instrument [Line Items]

Line of credit facility, outstanding amount

$ 74,700,000

Repayments of lines of credit

$ 5,300,000

SEACOR Marine Foreign Holdings Credit Facility | Tranche A

Debt Instrument [Line Items]

Debt instrument, maturity date

Sep. 30, 2023

Loan principal amount

$ 19,800,000

SEACOR Marine Foreign Holdings Credit Facility | Tranche B

Debt Instrument [Line Items]

Loan principal amount

$ 54,900,000

SEACOR Marine Foreign Holdings Credit Facility | SOFR | Tranche B

Debt Instrument [Line Items]

Debt instrument, maturity date

Sep. 30, 2023

Debt instrument, extended maturity date

Mar. 31, 2026

Margin percentage

4.75%

SEACOR Marine Foreign Holdings Credit Facility | Minimum | Tranche A

Debt Instrument [Line Items]

Margin percentage

3.75%

SEACOR Marine Foreign Holdings Credit Facility | Maximum | Tranche A

Debt Instrument [Line Items]

Margin percentage

4.75%

Convertible Senior Notes due 2023 (Old Convertible Notes)

Debt Instrument [Line Items]

Debt instrument, interest rate

4.25%

3.75%

Convertible debt, total

$ 125,000,000

$ 175,000,000

Debt instrument, convertible, conversion ratio

23.26

Embedded derivative, fair value of embedded derivative liability

$ 27,300,000

Interest rate

9.29%

7.95%

Debt instrument, face amount

$ 1,000

Senior PIK Toggle Notes due 2026

Debt Instrument [Line Items]

Convertible debt, total

$ 90,000,000

Senior PIK Toggle Notes due 2026 | Minimum

Debt Instrument [Line Items]

Debt instrument, interest rate

8%

Senior PIK Toggle Notes due 2026 | Maximum

Debt Instrument [Line Items]

Debt instrument, interest rate

9.50%

Convertible Senior Notes due 2026

Debt Instrument [Line Items]

Debt instrument, interest rate

4.25%

Convertible debt, total

$ 35,000,000

Guaranteed Notes

Debt Instrument [Line Items]

Debt instrument, maturity date

Jul. 01, 2026

Convertible debt, total

$ 90,000,000

Notes redeemable denomination amount

10,000,000

Debt instrument, redemption, description

SEACOR Marine may redeem some or all of the Guaranteed Notes at any time in minimum denominations of $10.0 million, upon not less than 30 nor more than 60 calendar days’ notice, at a price equal to (a) 101% of the principal amount of the Guaranteed Notes redeemed, if redeemed prior to October 1, 2024 and (b) 100% of the principal amount of the Guaranteed Notes redeemed, if redeemed on or after October 1, 2024, in either case plus accrued and unpaid interest, if any, to, but not including, the redemption date, provided, SEACOR Marine may not redeem the Guaranteed Notes if the principal amount of Guaranteed Notes and New Convertible Notes outstanding will be equal to or less than $50.0 million in the aggregate, unless SEACOR Marine redeems all of the Guaranteed Notes in whole.

Convertible notes outstanding

$ 50,000,000

Guaranteed Notes | Cash Interest

Debt Instrument [Line Items]

Debt instrument, interest rate

8%

Guaranteed Notes | Minimum

Debt Instrument [Line Items]

Notes redeemable denomination amount

$ 10,000,000

Guaranteed Notes | Redeemed On or After October 1, 2024

Debt Instrument [Line Items]

Redemption, percentage of principal amount

100%

Guaranteed Notes | Redeemed On or After October 1, 2023 but Prior to October 1, 2024

Debt Instrument [Line Items]

Redemption, percentage of principal amount

101%

Guaranteed Note Hybrid Interest

Debt Instrument [Line Items]

Debt instrument, interest rate

9.50%

Guaranteed Note Hybrid Interest Payment in Cash

Debt Instrument [Line Items]

Debt instrument, interest rate

4.25%

Guaranteed note hybrid interest Payment in Kind [Member]

Debt Instrument [Line Items]

Debt instrument, interest rate

5.25%

Old Convertible Notes

Debt Instrument [Line Items]

Debt instrument, maturity date

Jul. 01, 2026

Convertible debt, total

$ 35,000,000

$ 125,000,000

Debt instrument, convertible, conversion ratio

85.1064

Debt instrument, convertible, conversion price | $ / shares

$ 11.75

Redemption, percentage of principal amount

4.25%

Debt instrument, face amount

$ 1,000

Debt instrument, conversion description

SEACOR Marine has the right to cause the mandatory conversion of the New Convertible Notes into Common Stock if the daily VWAP of the Common Stock equals or exceeds (A) in the case of New Convertible Notes held by affiliates of Carlyle, 150% of the Conversion Price and (B) in the case of New Convertible Notes held by any Person other than Carlyle, 115% of the Conversion Price, in each case for each of the 20 consecutive trading days.

Debt instrument, percentage of new convertible notes to be purchased

100%

Debt instrument, percentage of new convertible notes to be redeemed

100%

New Convertible Notes

Debt Instrument [Line Items]

Debt instrument, maturity date

Jul. 01, 2026

Interest rate

9.46%

Debt instrument, convertible, conversion price | $ / shares

$ 11.75

Redemption, percentage of principal amount

4.25%

Debt instrument, face amount

$ 1,000

Debt instrument, conversion description

SEACOR Marine has the right to cause the mandatory conversion of the New Convertible Notes into Common Stock if the daily volume-weighted average price (“VWAP”) of the Common Stock equals or exceeds (A) in the case of New Convertible Notes held by affiliates of Carlyle, 150% of the Conversion Price and (B) in the case of New Convertible Notes held by any Person other than affiliates of Carlyle, 115% of the Conversion Price, in each case for each of the 20 consecutive trading days.

Debt instrument, percentage of new convertible notes to be purchased

100%

Debt instrument, percentage of new convertible notes to be redeemed

100%

Unamortized discount

$ 3,700,000

$ 4,900,000

Issuance costs

400,000

600,000

Total net carrying amount

30,900,000

29,500,000

Amortization of debt discount and issue costs

1,400,000

300,000

Contractual interest expense

2,900,000

700,000

Total interest expense

4,300,000

$ 1,000,000

New Convertible Notes Carlyle Group

Debt Instrument [Line Items]

Debt instrument, conversion price percentage

150%

New Convertible Notes Other Than Carlyle Group

Debt Instrument [Line Items]

Debt instrument, conversion price percentage

115%

2023 SMFH Credit Facility

Debt Instrument [Line Items]

Bears fixed interest rate

11.75%

Percentage of ownership acquire previously

100%

Percentage of quarterly amortization

2.50%

Percentage of minimum equity ratio

35%

Percentage of maximum debt-to-capitalization ratio

65%

Payments on debt extinguishment costs

(1,800,000)

Unamortized debt issuance costs

$ 200,000

Indebtedness

$ 104,800,000

Debt instrument payment terms

The loan may be prepaid at any time in amounts of $1,000,000 or greater, subject to: (a) prior to the 12-month anniversary of funding, a premium equal to the remaining unpaid interest due over the first 15 months of the loan, and (b) after the 12-month anniversary of funding and prior to the 30-month anniversary of funding, a decreasing premium ranging from 3.00% to 1.00% of the amount prepaid

2023 SMFH Credit Facility | Minimum

Debt Instrument [Line Items]

Percentage of decreasing premium

1%

Principal repayment of loan

$ 1,000,000

Cash and Cash Equivalents, Percentage

7.50%

Cash and Cash Equivalents

$ 20

2023 SMFH Credit Facility | Maximum

Debt Instrument [Line Items]

Percentage of decreasing premium

3%

2018 SMFH Credit Facility

Debt Instrument [Line Items]

Indebtedness

$ 61,100,000

Seacor Offshore OSV Credit Facility

Debt Instrument [Line Items]

Indebtedness

$ 15,100,000

SEACOR Alpine Credit Facility

Debt Instrument [Line Items]

Bears fixed interest rate

10.25%

Line of credit facility, maximum borrowing capacity

$ 28,000,000

Debt instrument payment terms

The loan may be prepaid at any time in amounts of $500,000 or greater, subject to the payment of prepayment interest in respect of the loan or tranche (or portions thereof) being prepaid as follows: (A) if such prepayment is made prior to the first anniversary of the drawdown date, an amount equal to the greater of (x) the amount of unpaid interest which would have accrued until the first anniversary of the drawdown date and (y) 1.5% of the principal amount of the loan being prepaid, (B) if such prepayment is made on or after the first anniversary of the drawdown date but prior to the third anniversary of the drawdown date, 1.0% of the principal amount of the loan being prepaid, and (C) if such prepayment is made on or after the third anniversary of the drawdown date, no prepayment interest shall be payable.

Prepayment interest

0

SEACOR Alpine Credit Facility | Tranche A

Debt Instrument [Line Items]

Repaid principal amount

$ 100,000

Number of installments | Installments

8

SEACOR Alpine Credit Facility | Tranche B

Debt Instrument [Line Items]

Repaid principal amount

$ 140,000

Number of installments | Installments

24

SEACOR Alpine Credit Facility | Tranche C

Debt Instrument [Line Items]

Repaid principal amount

$ 100,000

SEACOR Alpine Credit Facility | First Anniversary

Debt Instrument [Line Items]

Prepayment interest rate

1.50%

SEACOR Alpine Credit Facility | Third Anniversary

Debt Instrument [Line Items]

Prepayment interest rate

1%

SEACOR Alpine Credit Facility | Minimum

Debt Instrument [Line Items]

Principal repayment of loan

$ 500,000

SEACOSCO Acquisition Debt

Debt Instrument [Line Items]

Indebtedness

$ 13,700,000

Tarahumara Shipyard Financing

Debt Instrument [Line Items]

Bears fixed interest rate

6%

Debt instrument, maturity year

2025

Debt instrument, face amount

$ 6,500,000

Indebtedness

$ 3,900,000

Percentage of discount to book value

7%

7%

Sea-Cat Crewzer III

Debt Instrument [Line Items]

Repayments of long-term debt, total

$ 3,100,000

Interest rate

2.76%

Debt instrument, face amount | €

€ 27.6

Proceeds from issuance of debt

$ 7,100,000

$ 22,800,000

Debt issuance costs, gross

$ 2,700,000

Term Loan to Acquire Two Vessels

Debt Instrument [Line Items]

Debt instrument, face amount

$ 11,000,000

SEACOR 88/888 Term Loan

Debt Instrument [Line Items]

Long-term debt

$ 5,500,000

Percentage of debt obligations outstanding

50%

Indebtedness

$ 11,000,000

SEACOR 88/888 Term Loan | Minimum | SOFR

Debt Instrument [Line Items]

Credit facility, interest rate

3.75%

SEACOR 88/888 Term Loan | Maximum | SOFR

Debt Instrument [Line Items]

Credit facility, interest rate

4.75%

Convertible Senior Notes Converted to Warrants Carlyle Group

Debt Instrument [Line Items]

Debt instrument, convertible, conversion ratio

37.73

Class of warrant or right, exercise price of warrants or rights | $ / shares

$ 0.01

$ 0.01

Debt conversion, original debt, amount

$ 50,000,000

Debt conversion, converted instrument, shares issued | shares

1,886,792

Debt instrument, convertible, conversion price | $ / shares

$ 26.50

Warrants and rights outstanding, term

25 years

Debt instrument, face amount

$ 1,000

SEACOSCO Acquisition Debt

Debt Instrument [Line Items]

Purchase price payable for equity method investment in first year

$ 1,000,000

Purchase price payable for equity method investment in second year

2,500,000

Purchase price payable for equity method investment in third year

2,500,000

Purchase price payable for equity method investment in fourth year

$ 13,700,000

Purchase price fixed accrued interest rate in first year

1.50%

Purchase price fixed accrued interest rate in second year

7%

Purchase price fixed accrued interest rate in third year

7.50%

Purchase price fixed accrued interest rate in fourth year

8%

Number of vessels owned | Vessel

8

Number of vessels delivered to the company | Vessel

7

SEACOR Offshore Delta LLC

Debt Instrument [Line Items]

Percentage of membership interest acquired

50%

Purchase price payable for membership interest

$ 28,200,000

Purchase price payable to sellers at closing of transaction

$ 8,400,000

Business acquisition, amortization period of purchase price

10 years

Debt instrument, description of floating interest rate basis

three-month LIBOR plus 4.0

Debt instrument, basis spread on floating interest rate

4%

[1] Excludes five PSVs acquired as part of the OSV Partners Acquisition in 2021.

Long Term Debt - Schedule of Ga

Long Term Debt - Schedule of Gain on Transactions Under Conditional Payoff Agreement (Details) - USD ($) $ in Thousands		12 Months Ended
	Jun. 24, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 353,024	$ 363,794
Unamortized debt discount		(32,885)	(37,511)
Cash Paid		$ (29,165)	$ (38,152)	$ (78,124)
Conditional Payoff Agreement
Debt Instrument [Line Items]
Unamortized debt discount	$ (4,600)
Current Liabilities	112,749
Transaction Fees	(755)
Cash Paid	(27,500)
Hull and Machinery Insurance Proceeds	(22,500)
Gain on Troubled Debt Restructuring	61,994
Falcon Global U S A Term Loan Facility | Conditional Payoff Agreement
Debt Instrument [Line Items]
Long-term Debt, Gross	102,349
Falcon Global USA Revolver | Conditional Payoff Agreement
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 15,000

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Taxes [Line Items]
Income tax benefit and equity in earnings (losses)	50%	50%
Effective income tax rate reconciliation, percent, total	216.20%	12.30%	173.40%
Effective income tax rate reconciliation, at federal statutory income tax rate, percent	21%	21%	21%
Suspended interest deductible	$ 1.8
Interest expense suspended, limitation percentage	30%
Operating loss carryforwards, percentage of taxable income, utilization limitation	80%
Operating loss carryforwards, total	$ 1.8
Operating loss carryforwards, expiration period	20 years
Operating loss carry forwards expiration year	2037
Operating loss carryforwards, valuation allowance, total	$ 4.9

Income Taxes - Schedule of (Los

Income Taxes - Schedule of (Loss) Income before Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Taxes [Line Items]
(Loss) Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	$ (4,071)	$ (70,078)	$ 6,627
United States
Income Taxes [Line Items]
(Loss) Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	(3,576)	(48,037)	34,955
Foreign
Income Taxes [Line Items]
(Loss) Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	(335)	(21,881)	(29,425)
Eliminations
Income Taxes [Line Items]
(Loss) Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	$ (160)	$ (160)	$ 1,097

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Federal, current	$ (18)	$ 90
State, current	47	(78)	$ 271
Foreign, current	13,831	8,473	6,362
Current income tax expense	13,860	8,485	6,633
Federal, deferred	(5,062)	7	4,892
State, deferred	8	90	(32)
Foreign, deferred	(7)
Deferred income tax benefit	(5,061)	97	4,860
Income tax expense	$ 8,799	$ 8,582	$ 11,493

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory rate	21%	21%	21%
Income (loss) of foreign subsidiaries not includable in U.S. return and foreign withholding tax	223.40%	20.80%	141.60%
Non-Deductible Expenses	1.20%	0.30%	0.40%
JV equity earnings			3.80%
Sale of investments in 50% or less owned companies		11.10%
162(m) - Executive compensation	17.80%
Return to provision			0.40%
State Taxes	1.10%		2.70%
Subpart F Income	6.60%	0.70%	2%
Share Award Plans	(12.90%)	0.30%	1.50%
Other		0.10%
Effective Tax Rate	216.20%	12.30%	173.40%

Income Taxes - Schedule of Ef_2

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income tax benefit and equity in earnings (losses)	50%	50%

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax liabilities:
Property and equipment	$ 48,779	$ 56,618
Other	3,533	6,094
Total deferred tax liabilities	52,312	62,712
Deferred tax assets:
Federal Net Operating Loss Carryforwards	10,887	14,822
Other	10,632	9,619
Total deferred tax assets	21,519	24,441
Valuation Allowance	(4,925)	(2,508)
Total deferred tax assets	16,594	21,933
Net deferred tax liabilities	$ 35,718	$ 40,779

Derivative Instruments and He_3

Derivative Instruments and Hedging Strategies - Schedule of Fair Value of Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Designated as Hedging Instrument | Interest Rate Swap | Cash Flow Hedging
Derivative [Line Items]
Derivative Asset	$ 0	$ 526
Derivative Liability	0	0
Not Designated as Hedging Instrument | Forward Exchange Contract
Derivative [Line Items]
Derivative Asset	608	0
Derivative Liability	$ 0	$ 0

Derivative Instruments and He_4

Derivative Instruments and Hedging Strategies - Additional Information (Details) $ in Thousands, £ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2021 GBP (£)
Derivative [Line Items]
Derivative gains (losses) on cash flow hedges	$ 56	$ 1,608	$ 219
Interest Rate Swap
Derivative [Line Items]
Derivative gains (losses) on cash flow hedges	$ 56	1,608	219
Forward Exchange Contract | Windcat Workboats Holdings Ltd
Derivative [Line Items]
Proceeds to be received from sale of business | £				£ 31.5
Equity Investments in 50% or Less Owned Companies | Maximum
Derivative [Line Items]
Equity method investment, ownership percentage	50%
Equity Investments in 50% or Less Owned Companies | Minimum
Derivative [Line Items]
Equity method investment, ownership percentage	20%
Equity Investments in 50% or Less Owned Companies | Minimum | SEACOR Marine Foreign Holdings
Derivative [Line Items]
Equity method investment, ownership percentage	50%
Cash Flow Hedging
Derivative [Line Items]
Derivative gains (losses) on cash flow hedges	$ 500	$ 2,300	2,300
Derivative Liabilities | Fair Value Hedging
Derivative [Line Items]
Recognized gain (loss) on hedged item in fair value hedge	$ 600		$ 400

Derivative Instruments and He_5

Derivative Instruments and Hedging Strategies - Effect of Derivative Instruments on Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative [Line Items]
Derivative gains (losses) on cash flow hedges	$ 56	$ 1,608	$ 219
Interest Rate Swap
Derivative [Line Items]
Derivative gains (losses) on cash flow hedges	56	1,608	219
Joint Venture Interest Rate Swap
Derivative [Line Items]
Derivative gains (losses) on cash flow hedges	0	941	(588)
Interest Expense
Derivative [Line Items]
Reclassification of derivative losses on cash flow hedges	$ (571)	$ 694	$ 1,648

Derivative Instruments and He_6

Derivative Instruments and Hedging Strategies - Schedule of Gains (Losses) on Derivative Instruments not Designated as Hedging Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative [Line Items]
Gains (losses) on derivative instruments	$ 608	$ 0	$ 392
Embedded Derivative Financial Instruments
Derivative [Line Items]
Gains (losses) on derivative instruments	0	0	2
Foreign Exchange Option
Derivative [Line Items]
Gains (losses) on derivative instruments	$ 608	$ 0	$ 390

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Inputs, Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset	$ 0
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Receivables, Net, Current
Derivative Liability		$ 0
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Derivative Liability, Current
Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset	$ 608
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Receivables, Net, Current
Derivative Liability		$ 526
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Derivative Liability, Current
Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset	$ 0
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Receivables, Net, Current
Derivative Liability		$ 0
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Derivative Liability, Current

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Estimated Fair Values of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Reported Value Measurement
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	$ 84,131	$ 43,045
Long-term debt, including current portion	315,909	321,631
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	84,131	43,045
Long-term debt, including current portion	0	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	0	0
Long-term debt, including current portion	307,653	314,979
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	0	0
Long-term debt, including current portion	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) Investment
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Impairment charges		$ 2,900
Impairment of long-lived assets owned or leased in vessels		2,900
Number of marked investments, at equity, in 50% or less owned companies | Investment			1
Investments, at equity, in 50% or less owned companies	$ 4,125	3,024
Fast Support Vessel
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Impairment of long-lived assets held for sale		900
Anchor Handling Towing Supply
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Impairment of long-lived assets owned or leased in vessels	$ 700	700
Tower and Gangway
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Impairment of long-lived assets held for sale		$ 1,300
50% or Less Owned Companies | MEXMAR Offshore
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, at equity, in 50% or less owned companies			$ 0
Investment owned, at fair value, in 50% or less owned company			12,000
Investment owned excess amount fair value, in 50% or less owned company			9,400
Investment owned, balance, in 50% or less owned company			$ 2,600

Warrants - Additional Informati

Warrants - Additional Information (Details) - $ / shares	Nov. 09, 2023	Jan. 17, 2023	Dec. 23, 2021	Dec. 31, 2023	Oct. 05, 2022	Dec. 31, 2021
Class Of Warrant Or Right [Line Items]
Class of warrant or right, exercised during period	17,635	117,515	48,809
Class of warrant or right, exercise price per share				$ 0.01	$ 0.01
Class of warrant or right, outstanding				1,304,333		1,439,483
Number of shares withheld in an exercise to purchase warrants as payment for the exercise	16	121	149
Warrants Transactions
Class Of Warrant Or Right [Line Items]
Class of warrant or right, exercise price per share				$ 0.01
Class of warrant or right, number of securities called by warrants or rights				2,560,456

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details)					3 Months Ended	12 Months Ended
	Nov. 09, 2023 shares	Nov. 01, 2023 USD ($)	Jan. 17, 2023 shares	Dec. 23, 2021 shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares	Dec. 31, 2021 USD ($) shares		Dec. 31, 2020 USD ($)
Class Of Stock [Line Items]
Class of warrant or right, exercised during period	17,635		117,515	48,809
Class of warrant or right, outstanding					1,304,333	1,304,333		1,439,483
Number of shares withheld in an exercise to purchase warrants as payment for the exercise	16		121	149
Common stock, par value (in dollars per share) | $ / shares					$ 0.01	$ 0.01	$ 0.01
Proceeds from issuance of common stock | $					$ 77,623
Acquired						1	1	1	[1]
Common stock value | $					280,000	$ 280,000	$ 272,000
Cumulative Effect of New Accounting Principle in Period of Adoption | $					374,224,000	$ 374,224,000	$ 379,146,000	$ 446,541,000		$ 401,836,000
Exchange Warrants
Class Of Stock [Line Items]
Number of shares withheld in an exercise to purchase warrants as payment for the exercise	16
ATM Program
Class Of Stock [Line Items]
Consideration received from sale of stock | $		$ 25,000,000
Proceeds from issuance of common stock | $					$ 23,590
Common Stock [Member] | ATM Program
Class Of Stock [Line Items]
Number of shares issued					7,674
Share price | $ / shares					$ 13.1891	$ 13.1891
OSV Partners | Merger Agreement | Common Stock [Member] | Merger Consideration
Class Of Stock [Line Items]
Common stock issued								1,567,935
OSV Partners I | Merger Agreement | Common Stock [Member] | Merger Consideration
Class Of Stock [Line Items]
Common stock issued								531,872
OSV Partners I | Merger Agreement | Common Stock [Member] | PIK Loan Consideration | Limited Partner
Class Of Stock [Line Items]
Common stock issued								1,036,063
[1] Excludes five PSVs acquired as part of the OSV Partners Acquisition in 2021.

Noncontrolling Interests in S_3

Noncontrolling Interests in Subsidiaries - Schedule of Noncontrolling Interests in the Company's Consolidated Subsidiaries (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Minority Interest [Line Items]
Noncontrolling interests in subsidiaries	$ 321	$ 321
VEESEA Holdings Inc.
Minority Interest [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners	1.80%
Noncontrolling interests in subsidiaries	$ 321	$ 321

Savings and Multi-employer Pe_2

Savings and Multi-employer Pension Plans - Additional Information (Details) $ in Thousands, £ in Millions						12 Months Ended
	Nov. 23, 2023 USD ($)	Nov. 23, 2023 GBP (£)	Jul. 01, 2022	Jan. 01, 2022	Jan. 01, 2019	Dec. 31, 2023 USD ($)	Dec. 31, 2023 GBP (£)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Pension And Other Postretirement Benefits Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay			4%	3%	1%					2%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Amount						$ 1,100		$ 800		$ 200
Other Defined Contribution Plan
Pension And Other Postretirement Benefits Disclosure [Line Items]
Defined contribution plan, cost						700		$ 300	$ 400
MNRPF
Pension And Other Postretirement Benefits Disclosure [Line Items]
Defined contribution plan, tri annual valuation	$ 1,500	£ 1.2
Defined contribution plan, payroll related operating expenses						$ 1,500	£ 1.2

Share Based Compensation - Addi

Share Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2019	Dec. 31, 2017	Jun. 07, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted (in shares)		0	0	0
Payments for distribution of restricted stock, spin-off						$ 2.7
Allocated share-based compensation expense, total		$ 6.3	$ 5	$ 5.5
Allocated share-based compensation expense, recognized tax benefit		7	3	0.2
Employee service share-based compensation, nonvested awards, compensation cost not yet recognized, total		$ 6.6	$ 6.3	$ 4.8
Exercise of options (in shares)	[1]	834	34,492	0
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Distribution of restricted stock in connection with spin-off						120,693
Employee service share-based compensation, nonvested awards, compensation cost not yet recognized, period for recognition				1 year 3 days
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period, weighted average grant date fair value		$ 9.67
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee service share-based compensation, nonvested awards, compensation cost not yet recognized, period for recognition				5 months 1 day
Performance Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period		3 years
2017 Equity Incentive Plan | Restricted Stock | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period		1 year
2017 Equity Incentive Plan | Restricted Stock | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period		4 years
2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares available for grant							6,005
2017 and 2020 Equity Incentive Plan | Employee Stock Option | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period		1 year
2017 and 2020 Equity Incentive Plan | Employee Stock Option | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period		4 years
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized					300,000
Share-based compensation arrangement by share-based payment award, discount from market price, purchase date						85%
Period of common stock reserved for issuance					10 years
2022 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized							2,450,000
Share-based compensation arrangement by share-based payment award, number of shares available for grant		1,812,963
2017, 2020 and 2022 Equity Incentive Plan | Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee service share-based compensation, nonvested awards, compensation cost not yet recognized, period for recognition		9 months 7 days	1 year 7 days
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period, weighted average grant date fair value		$ 9.67	$ 5.92	$ 5.42
2017, 2020 and 2022 Equity Incentive Plan | Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee service share-based compensation, nonvested awards, compensation cost not yet recognized, period for recognition			2 months 1 day
[1] The intr insic value of the options exercised was less than $ 0.1 million.

Share Based Compensation - Sche

Share Based Compensation - Schedule of Equity Incentive Plan Transactions (Details) - shares		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding as of the beginning of year (in shares)		1,026,865		1,061,357
Granted (in shares)		0		0		0
Exercise of options (in shares)	[1]	(834)		(34,492)		0
Forfeited (in shares)	[2]	0		0		(59,184)
Outstanding as of the end of year (in shares)		1,026,031		1,026,865		1,061,357
Director Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted (in shares)		60,938		60,787		189,030
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding as of the beginning of year (in shares)		1,682,193	[3]	1,163,090	[3]	436,714
Granted (in shares)		660,307		1,036,605		933,705
Vested (in shares)		(685,416)		(514,002)		(202,079)
Forfeited (in shares)		(15,000)		(3,500)		(5,250)
Outstanding as of the end of year (in shares)	[3]	1,642,084		1,682,193		1,163,090
Outstanding as of the beginning of year (in shares)						1,120,541
[1] The intr insic value of the options exercised was less than $ 0.1 million. Forfeitures in 2021 includes 71,684 options forfeited as of December 31, 2021, netted with an adjustment of 12,500 previously granted. Excludes 156,620 , 216,172 and 354,964 grants of performance-based stock units as of December 31, 2023, 2022 and 2021 , respectively, that are not considered outstanding until such time that they become probable to vest.

Share Based Compensation - Sc_2

Share Based Compensation - Schedule of Equity Incentive Plan Transactions (Details) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2021	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Intrinsic value of options exercised	$ 1.7
Forfeiture, gross		71,684
Grants in previous period		12,500
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Intrinsic value of options exercised	$ 0.1
Performance Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares outstanding	156,620	354,964	216,172

Share Based Compensation - Sc_3

Share Based Compensation - Schedule of Restricted Stock Transactions (Details) - Restricted Stock - $ / shares		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding as of the beginning of year (in shares)		1,682,193	[1]	1,163,090	[1]	436,714
Non-Vested, weight average grant price (in dollars per share)		$ 5.68
Granted (in shares)		660,307		1,036,605		933,705
Granted, weight average grant price (in dollars per share)		$ 9.67
Vested (in shares)		(685,416)		(514,002)		(202,079)
Vested, weight average grant price (in dollars per share)		$ 10.12
Forfeited (in shares)		(15,000)		(3,500)		(5,250)
Forfeited, weight average grant price (in dollars per share)		$ 5.82
Outstanding as of the end of year (in shares)	[1]	1,642,084		1,682,193		1,163,090
Non-Vested, weight average grant price (in dollars per share)		$ 7.53		$ 5.68
[1] Excludes 156,620 , 216,172 and 354,964 grants of performance-based stock units as of December 31, 2023, 2022 and 2021 , respectively, that are not considered outstanding until such time that they become probable to vest.

Share Based Compensation - Sc_4

Share Based Compensation - Schedule of Stock Option Transactions (Details) - $ / shares		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement [Abstract]
Outstanding, shares (in shares)		1,026,865
Granted, shares (in shares)		0		0	0
Exercise of options (in shares)	[1]	(834)		(34,492)	0
Forfeited, shares (in shares)		0
Outstanding, shares (in shares)		1,026,031	[2]	1,026,865
Exercisable, shares (in shares)	[3]	1,026,031
Non-Vested, weight average grant price (in dollars per share)		$ 12.66
Granted, weight average grant price (in dollars per share)		0
Exercised (in dollars per share)		6.97
Forfeited, weight average grant price (in dollars per share)		0
Non-Vested, weight average grant price (in dollars per share)		12.66	[2]	$ 12.66
Exercisable, weight average grant price (in dollars per share)	[3]	$ 12.66
[1] The intr insic value of the options exercised was less than $ 0.1 million. The weighted average remaining contractual term is 4.8 years and the intrinsic value of the options exercised was $ 1.7 million. The weighted average remaining contractual term is 4.8 years and the intrinsic value of the options exercisable was $ 1.7 million.

Share Based Compensation - Sc_5

Share Based Compensation - Schedule of Stock Option Transactions (Details) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2021
Share-Based Payment Arrangement [Abstract]
Share-based compensation arrangement by share-based payment award, options, exercisable, weighted average remaining contractual term	4 years 9 months 18 days
Forfeiture, gross		71,684
Grants in previous period		12,500
Intrinsic value of options exercised	$ 1.7
Weighted average remaining contractual term, outstanding	4 years 9 months 18 days
Intrinsic value of options exercisable	$ 1.7

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Transactions with SEACOR Holdings) (Details) - Tax Refund Agreement [Member] - USD ($) $ in Millions			1 Months Ended	12 Months Ended
	Mar. 31, 2021	Jun. 26, 2020	Apr. 30, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Proceeds from Income Tax Refunds		$ 32.3	$ 19.8
Interest Received		$ 1.1
Percentage of net operating losses facilitate tax savings		35%
Transaction fee		$ 3
Cash tax refunds without restrict to use		$ 23.1
Tax Refunds Restricted Cash				$ 7
S E A C O R Holdings [Member]
Related Party Transaction [Line Items]
Proceeds from Income Tax Refunds	$ 12.5
Cash tax refunds with restrict to use				$ 8.1

Related Party Transactions - _2

Related Party Transactions - Additional Information (Transactions Regarding OSV Partners) (Details) - USD ($) $ in Millions		1 Months Ended	12 Months Ended
	Oct. 29, 2021	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2021	Dec. 31, 2018	Dec. 31, 2017	Dec. 30, 2021	Jul. 23, 2021
Related Party Transaction [Line Items]
Investments								$ 2.6
Vessel management fees					$ 0.6	$ 0.6
Class A Preferred Interests
Related Party Transaction [Line Items]
Proceeds from issuance of debt					5
Second Lien Debt
Related Party Transaction [Line Items]
Proceeds from Issuance of Redeemable Preferred Stock					5
Caroline I I
Related Party Transaction [Line Items]
Equity Method Investment, Ownership Amount			$ 0.5
Caroline I I | OSV Partners Merger Agreement
Related Party Transaction [Line Items]
Common stock issued				36,570
Mr. Fabrikant
Related Party Transaction [Line Items]
Investments							$ 0.3
Gellert
Related Party Transaction [Line Items]
Investments							0.4
Llorca
Related Party Transaction [Line Items]
Investments							$ 0.2
OSV Partners I | Two Thousand Seventeen Preferred Interests
Related Party Transaction [Line Items]
Preferred limited partnership interests			$ 6
OSV Partners
Related Party Transaction [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners			30.40%
OSV Partners | Class A Preferred Interests
Related Party Transaction [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners			43%
OSV Partners | Two Thousand Seventeen Preferred Interests
Related Party Transaction [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners			38.60%
OSV Partners I
Related Party Transaction [Line Items]
Percentage of initial limited partner interests and general partner interests and initial lp interests held by unrelated third parties			30.40%
Proceeds from Sale of Interest in Partnership Unit					$ 10
OSV Partners I | Preferred Interests and Class A Preferred Interests | Merger Consideration
Related Party Transaction [Line Items]
Equity method investment, ownership percentage		80%		80%
OSV Partners I | Initial LP Interests partners | Merger Consideration
Related Party Transaction [Line Items]
Equity method investment, ownership percentage		20%		20%
OSV Partners I | Caroline
Related Party Transaction [Line Items]
Equity Method Investment, Ownership Amount			$ 1
Equity method investment, ownership percentage			2.60%
OSV Partners I | Caroline I I
Related Party Transaction [Line Items]
Equity method investment, ownership percentage			1.30%
2017 Preferred Interests Caroline | OSV Partners I
Related Party Transaction [Line Items]
Preferred limited partnership interests			$ 0.2
Noncontrolling Interest, ownership percentage by parent			3.30%
2017 Preferred Interests Caroline II | OSV Partners I
Related Party Transaction [Line Items]
Preferred limited partnership interests			$ 0.1
Noncontrolling Interest, ownership percentage by parent			1.70%
Class A Preferred Interests Caroline
Related Party Transaction [Line Items]
Equity method investment, ownership percentage					2.60%
Limited Partners' Capital Account					$ 0.1
P I K Loan Debt And Caroline
Related Party Transaction [Line Items]
Equity method investment, ownership percentage					2.60%
Limited Partners' Capital Account					$ 0.1
Class A Preferred Interests Caroline II
Related Party Transaction [Line Items]
Equity method investment, ownership percentage					1.30%
Limited Partners' Capital Account					$ 0.1
P I K Loan Debt And Caroline II
Related Party Transaction [Line Items]
Equity method investment, ownership percentage					1.30%
Limited Partners' Capital Account					$ 0.1
P I K Loan Debt And Caroline II | OSV Partners
Related Party Transaction [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners			43%
Exchange | O S V Credit Facility
Related Party Transaction [Line Items]
Loan acquired	$ 2.2
Third Party Lender | O S V Credit Facility
Related Party Transaction [Line Items]
Loan acquired	4.1
Principal | O S V Credit Facility
Related Party Transaction [Line Items]
Loan acquired	$ 22.1
OSV Partner Common Stock [Member] | OSV Partners Merger Agreement
Related Party Transaction [Line Items]
Common stock issued				1,567,935
OSV Partner Common Stock [Member] | Caroline | OSV Partners Merger Agreement
Related Party Transaction [Line Items]
Common stock issued				73,107
OSV Partner Common Stock [Member] | Caroline | Merger Consideration And Payment In Kind Loan Consideration
Related Party Transaction [Line Items]
Common stock issued				26,557
OSV Partner Common Stock [Member] | Mr. Fabrikant | Caroline | Merger Consideration And Payment In Kind Loan Consideration
Related Party Transaction [Line Items]
Common stock issued				20,172
OSV Partner Common Stock [Member] | Gellert | Caroline | Merger Consideration And Payment In Kind Loan Consideration
Related Party Transaction [Line Items]
Common stock issued				22,353
OSV Partner Common Stock [Member] | Llorca | Caroline | Merger Consideration And Payment In Kind Loan Consideration
Related Party Transaction [Line Items]
Common stock issued				9,174
OSV Partners Common Stock One [Member] | Merger Consideration
Related Party Transaction [Line Items]
Common stock issued				531,872
OSV Partners Common Stock One [Member] | PIK Loan Consideration | OSV Partners Merger Agreement
Related Party Transaction [Line Items]
Common stock issued				1,036,063
OSV Partners | Caroline
Related Party Transaction [Line Items]
Business combination, assumed and guarantee amount		$ 18.1
OSV Partners | Mr. Fabrikant | Caroline | Merger Consideration And Payment In Kind Loan Consideration
Related Party Transaction [Line Items]
Equity method investment, ownership percentage		1.30%		1.30%
OSV Partners | Gellert | Caroline | Merger Consideration And Payment In Kind Loan Consideration
Related Party Transaction [Line Items]
Equity method investment, ownership percentage		1.40%		1.40%
OSV Partners | Llorca | Caroline | Merger Consideration And Payment In Kind Loan Consideration
Related Party Transaction [Line Items]
Equity method investment, ownership percentage		0.60%		0.60%

Related Party Transactions - _3

Related Party Transactions - Additional Information (Transactions with Carlyle and Transactions with CME) (Details) - USD ($)

1 Months Ended

12 Months Ended

Nov. 09, 2023

Jan. 17, 2023

Oct. 05, 2022

Sep. 29, 2022

Dec. 23, 2021

Dec. 09, 2021

Jul. 23, 2021

Jun. 01, 2021

Dec. 20, 2018

Dec. 16, 2016

Jul. 31, 2020

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2019

Dec. 10, 2021

Dec. 31, 2020

Dec. 28, 2018

May 02, 2018

Related Party Transaction [Line Items]

Minimum cash requirement

$ 16,676,000

$ 3,082,000

Investments

$ 2,600,000

Proceeds from sale of investment in equity investees

$ 66,000,000

0

66,000,000

$ 0

Prepayment of outstanding loan

$ 1,827,000

$ 2,271,000

$ 755,000

Class of warrant or right, exercise price of warrants or rights

$ 0.01

$ 0.01

Class of warrant or right, outstanding

1,304,333

1,439,483

Class of warrant or right, exercised during period

17,635

117,515

48,809

Indebtedness

$ 95,000,000

Total purchase price

$ 30,200,000

Gain (loss) on equity earnings

$ 2,600,000

Distribution Received

12,000,000

Excess of distribution received

9,400,000

Guaranteed Notes

Related Party Transaction [Line Items]

Debt instrument, redemption, description

SEACOR Marine may redeem some or all of the Guaranteed Notes at any time in minimum denominations of $10.0 million, upon not less than 30 nor more than 60 calendar days’ notice, at a price equal to (a) 101% of the principal amount of the Guaranteed Notes redeemed, if redeemed prior to October 1, 2024 and (b) 100% of the principal amount of the Guaranteed Notes redeemed, if redeemed on or after October 1, 2024, in either case plus accrued and unpaid interest, if any, to, but not including, the redemption date, provided, SEACOR Marine may not redeem the Guaranteed Notes if the principal amount of Guaranteed Notes and New Convertible Notes outstanding will be equal to or less than $50.0 million in the aggregate, unless SEACOR Marine redeems all of the Guaranteed Notes in whole.

Notes redeemable denomination amount

$ 10,000,000

Convertible notes outstanding

$ 50,000,000

Debt instrument, maturity date

Jul. 01, 2026

Convertible debt, total

$ 90,000,000

Guaranteed Notes | Redeemed On or After October 1, 2023 but Prior to October 1, 2024

Related Party Transaction [Line Items]

Debt Instrument, Redemption Price, Percentage

101%

Guaranteed Notes | Redeemed On or After October 1, 2024

Related Party Transaction [Line Items]

Debt Instrument, Redemption Price, Percentage

100%

Guaranteed Note Cash Interest

Related Party Transaction [Line Items]

Debt instrument, interest rate

8%

Guaranteed Note Hybrid Interest Payment in Cash

Related Party Transaction [Line Items]

Debt instrument, interest rate

4.25%

Guaranteed Note Hybrid Interest

Related Party Transaction [Line Items]

Debt instrument, interest rate

9.50%

Guaranteed Note Hybrid Interest Payment in Kind

Related Party Transaction [Line Items]

Debt instrument, interest rate

5.25%

Old Convertible Notes

Related Party Transaction [Line Items]

Debt Instrument, Redemption Price, Percentage

4.25%

Debt instrument, percentage of new convertible notes to be purchased

100%

Debt instrument, percentage of new convertible notes to be redeemed

100%

Debt instrument, maturity date

Jul. 01, 2026

Convertible debt, total

$ 35,000,000

$ 125,000,000

Debt instrument, conversion description

SEACOR Marine has the right to cause the mandatory conversion of the New Convertible Notes into Common Stock if the daily VWAP of the Common Stock equals or exceeds (A) in the case of New Convertible Notes held by affiliates of Carlyle, 150% of the Conversion Price and (B) in the case of New Convertible Notes held by any Person other than Carlyle, 115% of the Conversion Price, in each case for each of the 20 consecutive trading days.

Debt instrument, convertible, conversion ratio

85.1064

Debt instrument, face amount

$ 1,000

Debt instrument, convertible, conversion price

$ 11.75

MexMar Original Facility Agreement

Related Party Transaction [Line Items]

Debt instrument, face amount

28,800,000

MexMar Second Amended and Restated Term Loan Credit Facility Agreement

Related Party Transaction [Line Items]

Minimum cash requirement

$ 10,000,000

Debt instrument, maturity date

Jan. 23, 2025

Interest rate

4.70%

MexMar Third A&R Facility Agreement

Related Party Transaction [Line Items]

Minimum cash requirement

2,500,000

Principal repayment of loan

$ 5,000,000

Debt Instrument, Frequency of Periodic Payment

four quarterly installments

Debt instrument, maturity date

Sep. 30, 2023

Prepayment of outstanding loan

$ 8,800,000

Debt instrument, face amount

$ 20,000,000

Interest rate

5%

Lender Non Recourse

Related Party Transaction [Line Items]

Indebtedness

70,000,000

MexMar

Related Party Transaction [Line Items]

Transaction fee

$ 200,000

Indebtedness

15,000,000

Percentage transferred

49%

MEXMAR Offshore

Related Party Transaction [Line Items]

Indebtedness

10,000,000

Contributed capital

$ 5,000,000

Aggregate purchase price

$ 9,400,000

MEXMAR Offshore Brazil

Related Party Transaction [Line Items]

Aggregate purchase price

$ 0

Long-term debt, total

$ 70,000,000

Commitment to fund purchase

2,700,000

Notes Payable, Total

$ 1,960,000

MEXMAR Offshore Brazil | UP Off shores Debt

Related Party Transaction [Line Items]

Long-term debt, total

$ 5,500,000

CME

Related Party Transaction [Line Items]

Equity method investment, ownership percentage

49%

SEACOR Marlin LLC

Related Party Transaction [Line Items]

Equity method investment, ownership percentage

49%

Distribution Received

$ 2,500,000

OVH

Related Party Transaction [Line Items]

Equity method investment, ownership percentage

49%

Mexmar Offshore International

Related Party Transaction [Line Items]

Equity method investment, ownership percentage

50%

50%

Offshore Vessel Holdings

Related Party Transaction [Line Items]

Contributed capital

$ 10,000,000

Other Than Carlyle | Old Convertible Notes

Related Party Transaction [Line Items]

Debt instrument, conversion price percentage

115%

New Convertible Notes and Warrants

Related Party Transaction [Line Items]

Percentage of convertible notes converted into common stock

10%

Subsidiaries of CME

Related Party Transaction [Line Items]

Noncontrolling interest, ownership percentage by noncontrolling owners

51%

Subsidiaries of CME | OVH

Related Party Transaction [Line Items]

Noncontrolling interest, ownership percentage by noncontrolling owners

51%

Subsidiaries of CME | Mexmar Offshore International

Related Party Transaction [Line Items]

Equity method investment, ownership percentage

49%

Noncontrolling interest, ownership percentage by noncontrolling owners

51%

51%

Subsidiaries of CME | Offshore Vessel Holdings

Related Party Transaction [Line Items]

Noncontrolling interest, ownership percentage by noncontrolling owners

51%

Subsidiary of MexMar | SEACOR Marlin LLC

Related Party Transaction [Line Items]

Noncontrolling interest, ownership percentage by noncontrolling owners

51%

Subsidiary of MexMar | Mexmar Offshore International

Related Party Transaction [Line Items]

Equity method investment, ownership percentage

49%

Prior to the Closing of the Framework Agreement Transactions | Offshore Vessel Holdings

Related Party Transaction [Line Items]

Equity method investment, ownership percentage

49%

Prior to the Closing of the Framework Agreement Transactions | OTM

Related Party Transaction [Line Items]

Noncontrolling interest, ownership percentage by noncontrolling owners

51%

O P E M

Related Party Transaction [Line Items]

Loan in exchange

$ 10,000,000

Loan early repayment

10,500,000

Interest payable

$ 4,100,000

Carlyle Group

Related Party Transaction [Line Items]

Class of warrant or right, outstanding

1,304,333

Class of warrant or right, exercised during period

135,150

0

48,809

Carlyle Group | Old Convertible Notes

Related Party Transaction [Line Items]

Debt instrument, conversion price percentage

150%

Carlyle Group | New Convertible Notes and Guaranteed Notes

Related Party Transaction [Line Items]

Percentage of convertible notes converted into common stock

5%

Debt conversion, original debt, amount

$ 50,000,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) R$ in Thousands, £ in Millions, $ in Millions			12 Months Ended
	Nov. 23, 2023 USD ($)	Nov. 23, 2023 GBP (£)	Dec. 31, 2023 USD ($)	Dec. 31, 2023 GBP (£)	Dec. 31, 2023 BRL (R$)
Commitments And Contingencies [Line Items]
Unrecorded unconditional purchase obligation, total			$ 15.5
Unrecorded unconditional purchase obligation payable during 2024			13.5
Unrecorded unconditional purchase obligation payable during 2025			2
Unrecorded unconditional purchase obligation due within four years			$ 9.2
Deficiency Notice
Commitments And Contingencies [Line Items]
Cost allocation percentage			70%	70%
Deficiency Notice | Seabulk Overseas
Commitments And Contingencies [Line Items]
Cost allocation percentage			30%	30%
Minimum | Deficiency Notice
Commitments And Contingencies [Line Items]
Potential range of levies			$ 4.8		R$ 23500
Maximum | Deficiency Notice
Commitments And Contingencies [Line Items]
Potential range of levies			$ 2.7		R$ 12870
FSV Offshore Support Vessels
Commitments And Contingencies [Line Items]
Unrecorded unconditional purchase obligation, maximum quantity			1		1
MNRPF
Commitments And Contingencies [Line Items]
Defined contribution plan, tri annual valuation	$ 1.5	£ 1.2
Defined contribution plan, payroll related operating expenses			$ 1.5	£ 1.2

Major Customers and Segment I_3

Major Customers and Segment Information - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) Customer	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Segment Reporting Information [Line Items]
Revenues	$ 279,511	$ 217,325	$ 170,941
Income (loss) from equity method investments	$ 3,556	7,011	15,078
SEACOR Marine Arabia
Segment Reporting Information [Line Items]
Ownership percentage	45%
Customer Concentration Risk | Sales Revenue, Net | Seacor Marine Arabia
Segment Reporting Information [Line Items]
Revenues	$ 43,200	$ 30,100	$ 29,700
Concentration risk, percentage	15%	14%	17%
Customer Concentration Risk | Sales Revenue, Net | Ten Largest Customers
Segment Reporting Information [Line Items]
Concentration risk, percentage	73%	66%	81%
Geographic Concentration Risk | Sales Revenue, Net
Segment Reporting Information [Line Items]
Number of customer | Customer	10
Geographic Concentration Risk | Sales Revenue, Net | Non-US
Segment Reporting Information [Line Items]
Income (loss) from equity method investments	$ 3,600	$ 7,000	$ 15,400
Geographic Concentration Risk | Sales Revenue, Net | Azule Energy Angola S p A
Segment Reporting Information [Line Items]
Revenues	$ 42,400
Concentration risk, percentage	15%
Geographic Concentration Risk | Sales Revenue, Net | ExxonMobil
Segment Reporting Information [Line Items]
Revenues	$ 47,700	$ 39,600	$ 35,200
Concentration risk, percentage	17%	18%	21%
Geographic Concentration Risk | Stockholders' Equity | Non-US
Segment Reporting Information [Line Items]
Concentration risk, percentage	79%	72%	88%

Major Customers and Segment I_4

Major Customers and Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021
Segment Reporting Information [Line Items]
Operating Revenues	$ 279,511		$ 217,325		$ 170,941
Direct Costs and Expenses	159,650		171,985		127,406
Direct Vessel (Loss) Profit	119,861		45,340		43,535
Lease expense	2,748		3,869		6,085
Administrative and general	49,183		40,911		37,639
Depreciation and amortization	53,821		55,957		57,395
Other Costs and Expenses	105,752		100,737		101,119
Gains on Asset Dispositions and Impairments, Net	21,409		1,398		20,436
Operating Income (Loss)	35,518		(53,999)		(37,148)
Historical cost	918,823	[1]	967,683	[1]	1,008,080
Accumulated depreciation	(324,141)		(310,778)		(302,328)
Property and equipment	594,682		656,905		705,752
Total Assets	709,023	[2]	751,599	[3]	823,065	[4]
Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	251,385		203,534		159,835
Bareboat Charter
Segment Reporting Information [Line Items]
Operating Revenues	1,460		1,374		4,033
Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	26,666		12,417		7,073
Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	81,770		77,782		59,920
Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	26,826		31,496		24,117
Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	6,598		18,160		6,347
Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	9,956		9,962		8,667
Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	17,187		19,289		12,033
Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	17,313		15,296		16,322
UNITED STATES
Segment Reporting Information [Line Items]
Operating Revenues	59,528		60,800		20,643
Direct Costs and Expenses	42,446		50,639		18,796
Direct Vessel (Loss) Profit	17,082		10,161		1,847
Lease expense	536		998		2,621
Depreciation and amortization	14,685		17,444		15,712
Historical cost	209,262		232,740		240,717
Accumulated depreciation	(99,137)		(101,503)		(115,088)
Property and equipment	110,125		131,237		125,629
Total Assets	142,264	[2]	174,081	[3]	148,753	[4]
UNITED STATES | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	41,850		51,272		15,487
UNITED STATES | Bareboat Charter
Segment Reporting Information [Line Items]
Operating Revenues					1,549
UNITED STATES | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	17,678		9,528		3,607
UNITED STATES | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	26,110		25,201		8,836
UNITED STATES | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	5,146		7,049		3,394
UNITED STATES | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	2,314		8,978		2,082
UNITED STATES | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	3,752		4,831		2,632
UNITED STATES | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	3,697		3,345		1,204
UNITED STATES | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	1,427		1,235		648
Africa and Europe
Segment Reporting Information [Line Items]
Operating Revenues	90,311		59,897		42,930
Direct Costs and Expenses	51,633		44,379		33,111
Direct Vessel (Loss) Profit	38,678		15,518		9,819
Lease expense	1,498		1,691		1,281
Depreciation and amortization	15,346		13,708		12,856
Historical cost	272,272		285,303		218,544
Accumulated depreciation	(93,045)		(92,030)		(69,310)
Property and equipment	179,227		193,273		149,234
Total Assets	215,158	[2]	211,371	[3]	167,185	[4]
Africa and Europe | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	87,729		60,060		44,268
Africa and Europe | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	2,582		(163)		(1,338)
Africa and Europe | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	20,434		16,436		13,903
Africa and Europe | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	9,624		9,229		6,772
Africa and Europe | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	2,946		2,339		1,159
Africa and Europe | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	1,727		1,178		1,353
Africa and Europe | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	6,830		8,022		4,109
Africa and Europe | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	10,072		7,175		5,815
Middle East and Asia
Segment Reporting Information [Line Items]
Operating Revenues	70,752		52,842		53,672
Direct Costs and Expenses	38,947		49,616		43,629
Direct Vessel (Loss) Profit	31,805		3,226		10,043
Lease expense	360		156		472
Depreciation and amortization	14,760		16,331		17,985
Historical cost	267,079		286,745		340,225
Accumulated depreciation	(94,708)		(89,444)		(85,683)
Property and equipment	172,371		197,301		254,543
Total Assets	199,174	[2]	215,497	[3]	256,533	[4]
Middle East and Asia | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	66,407		52,080		53,146
Middle East and Asia | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	4,345		762		526
Middle East and Asia | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	20,786		22,376		22,191
Middle East and Asia | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	7,109		8,111		6,701
Middle East and Asia | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	(99)		6,569		2,639
Middle East and Asia | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	3,638		2,838		2,481
Middle East and Asia | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	3,552		5,089		3,459
Middle East and Asia | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	3,961		4,633		6,158
Latin America
Segment Reporting Information [Line Items]
Operating Revenues	58,920		43,786		53,696
Direct Costs and Expenses	26,624		27,351		31,870
Direct Vessel (Loss) Profit	32,296		16,435		21,826
Lease expense	354		1,024		1,711
Depreciation and amortization	9,030		8,474		10,842
Historical cost	170,210		162,895		208,594
Accumulated depreciation	(37,251)		(27,801)		(32,247)
Property and equipment	132,959		135,094		176,347
Total Assets	152,427	[2]	150,650	[3]	250,594	[4]
Latin America | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	55,399		40,122		46,934
Latin America | Bareboat Charter
Segment Reporting Information [Line Items]
Operating Revenues	1,460		1,374		2,484
Latin America | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	2,061		2,290		4,278
Latin America | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	14,440		13,769		14,990
Latin America | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	4,947		7,107		7,250
Latin America | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	1,437		274		467
Latin America | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	839		1,115		2,201
Latin America | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	3,108		2,833		3,261
Latin America | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	$ 1,853		$ 2,253		$ 3,701
[1] Includes property and equipment acquired in business acquisitions at acquisition date fair value and net of the impact of recognized impairment charges. Some of the Company’s vessels are pledged as security for certain loans. Total Assets exclude $ 71.3 million of corporate assets. Total Assets exclude $ 64.0 million of corporate assets. Total Assets exclude $ 89.4 million of corporate assets.

Major Customers and Segment I_5

Major Customers and Segment Information - Schedule of Segment Reporting Information, by Segment (Parenthetical) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Assets, Total	$ 780,336	$ 815,367
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Assets, Total	$ 71,300	$ 64,000	$ 89,400

Discontinued Operations - Addit

Discontinued Operations - Additional Information (Details) - Windcat Workboats Holdings Ltd - Discontinued Operations, Held-for-sale - USD ($) $ in Thousands		12 Months Ended
	Jan. 12, 2021	Dec. 31, 2021
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net income from operations	$ 200	$ 169
Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]	Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest

Discontinued Operations - Sched

Discontinued Operations - Schedule of Assets Held for Sale (Details) - USD ($) $ in Thousands		12 Months Ended
	Jan. 12, 2021	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2020
Assets from Discontinued Operations:
Current assets			$ 500	$ 6,750
Windcat Workboats Holdings Ltd | Discontinued Operations, Held-for-sale
Assets from Discontinued Operations:
Current assets					$ 10,138
Net property and equipment					34,580
Non-current assets					5,517
Assets from discontinued operations					50,235
Liability from Discontinued Operations:
Current liabilities					2,418
Long-term liabilities					28,509
Disposal Group, Including Discontinued Operation, Liabilities					$ 30,927
Operating Revenues:
Operating Revenues		$ 973
Costs and Expenses:
Operating		578
Direct Vessel Profit		395
General and Administrative Expenses		238
Lease Expense		24
Operating Income		133
Other Income (Expense)
Interest income		2
Interest expense		(39)
Foreign currency translation gain (loss)		89
Other Income (Expense)		52
Operating Income Before Equity Earnings of 50% or Less Owned Companies, Net of Tax		185
Operating Income Before Equity Earnings of 50% or Less Owned Companies		185
Equity in (Losses) Earnings of 50% or Less Owned Companies, Net of Tax		(16)
Net Income from Discontinued Operations	$ 200	$ 169
Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]	Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest
Windcat Workboats Holdings Ltd | Discontinued Operations, Held-for-sale | Time Charter
Operating Revenues:
Operating Revenues		$ 903
Windcat Workboats Holdings Ltd | Discontinued Operations, Held-for-sale | Other Revenue
Operating Revenues:
Operating Revenues		$ 70

Schedule II - Valuation and Q_3

Schedule II - Valuation and Qualifying Accounts - Schedule of Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Allowance for credit loss reserves (deducted from trade and notes receivable)	$ 1,650	$ 1,312	$ 582
Allowance for credit loss reserves (deducted from trade and notes receivable)	0	0	3
Allowance for credit loss reserves (deducted from trade and notes receivable)	3,519	489	863
Allowance for credit loss reserves (deducted from trade and notes receivable)	(626)	(151)	(136)
Allowance for credit loss reserves (deducted from trade and notes receivable)	$ 4,543	$ 1,650	$ 1,312