SEACOR Marine (SMHI) 10-Q 4 Nov 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Oct. 29, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Trading Symbol	SMHI
Entity Registrant Name	SEACOR Marine Holdings Inc.
Entity Central Index Key	0001690334
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		24,375,642
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	1-37966
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
Entity Incorporation, State or Country Code	DE
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common stock
Security Exchange Name	NYSE
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 42,194	$ 32,666
Restricted cash	4,160	3,352
Receivables:
Trade, net of allowance for credit loss accounts of $724 and $582 in 2021 and 2020, respectively	50,343	45,325
Other	13,750	10,924
Receivable from SEACOR Holdings		18,832
Tax Receivable	101	13,556
Inventories	476	576
Prepaid expenses and other	3,851	3,230
Assets held for sale		50,235
Total current assets	114,875	178,696
Property and Equipment:
Historical cost	989,910	1,012,873
Accumulated depreciation	(303,178)	(291,538)
Property and equipment	686,732	721,335
Construction in progress	15,577	32,327
Net property and equipment	702,309	753,662
Right-of-Use Asset - Operating Leases	4,670	7,134
Right-of-Use Asset - Finance Leases	108	129
Investments, at Equity, and Advances to 50% or Less Owned Companies	77,426	75,308
Other Assets	2,672	2,734
Total assets	902,060	1,017,663
Current Liabilities:
Current portion of operating lease liabilities	1,269	7,030
Current portion of financing lease liabilities	32	36
Current portion of long-term debt:
Recourse	28,875	26,734
Non-recourse		5,643
Accounts payable and accrued expenses	23,578	29,967
Due to SEACOR Holdings	276
Accrued wages and benefits	1,531	1,744
Accrued interest	3,236	1,664
Deferred revenue and unearned revenue	2,356	4,452
Accrued capital, repair, and maintenance expenditures	1,356	11,328
Accrued insurance deductibles and premiums	3,087	2,274
Accrued professional fees	1,195	975
Derivatives	2,476	4,591
Other current liabilities	5,872	4,439
Liabilities held for sale		30,927
Total current liabilities	75,139	131,804
Long-Term Operating Lease Liabilities	4,000	4,345
Long-Term Financing Lease Liabilities	84	105
Long-Term Debt:
Recourse	316,185	328,690
Non-recourse	5,456	111,820
Conversion Option Liability on Convertible Senior Notes	5	2
Deferred Income Taxes	43,463	35,822
Deferred Gains and Other Liabilities	2,925	3,239
Total liabilities	447,257	615,827
SEACOR Marine Holdings Inc. stockholders’ equity:
Common stock, $.01 par value, 60,000,000 shares authorized; 24,503,380 and 23,504,050 shares issued in 2021 and 2020, respectively	245	235
Additional paid-in capital	455,373	451,179
Retained Earnings (Accumulated deficit)	(7,059)	(51,839)
Shares held in treasury of 127,738 and 73,284, respectively, at cost	(1,120)	(848)
Accumulated other comprehensive gain, net of tax	7,044	2,790
Total stockholders equity	454,483	401,517
Noncontrolling interests in subsidiaries	320	319
Total equity	454,803	401,836
Total liabilities and equity	$ 902,060	$ 1,017,663

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Trade receivables, allowance for credit loss	$ 724	$ 582
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)	24,503,380	23,504,050
Shares held in treasury (in shares)	127,738	73,284

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Statements of Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Operating Revenues	$ 43,663	$ 36,224	$ 122,974	$ 105,816
Costs and Expenses:
Operating	33,448	24,719	92,370	65,583
Administrative and general	9,134	8,885	26,897	31,519
Lease expense	1,109	1,200	3,421	5,727
Depreciation and amortization	14,306	14,833	43,197	41,920
Costs and expenses	57,997	49,637	165,885	144,749
Gains (Losses) on Asset Dispositions and Impairments, Net	56	233	20,436	(15,792)
Operating (Loss)	(14,278)	(13,180)	(22,475)	(54,725)
Other Income (Expense):
Interest income	124	34	1,245	1,212
Interest expense	(6,403)	(8,312)	(21,731)	(22,403)
SEACOR Holdings guarantee fees		(11)	(7)	(36)
Gain on Debt Extinguishment			61,994
Derivative gains, net	2	5	387	5,204
Foreign currency gains (losses), net	245	(911)	(878)	(8)
Gain from return of investments in 50% or less owned companies and other, net	9,442		9,441
Nonoperating income expense	3,410	(9,195)	50,451	(16,031)
(Loss) Income from Continuing Operations Before Income Tax Benefit and Equity in Earnings of 50% or Less Owned Companies	(10,868)	(22,375)	27,976	(70,756)
Income Tax (Benefit) Expense	(725)	(3,120)	12,502	(24,789)
(Loss) Income from Continuing Operations Before Equity in Earnings of 50% or Less Owned Companies	(10,143)	(19,255)	15,474	(45,967)
Equity in Earnings Gains (Losses) of 50% or Less Owned Companies	4,314	(588)	10,584	1,518
(Loss) Income from Continuing Operations	(5,829)	(19,843)	26,058	(44,449)
Income on Discontinued Operations, Net of Tax (see Note 12)		1,766	22,925	314
Net (Loss) Income	(5,829)	(18,077)	48,983	(44,135)
Net Income (Loss) Attributable to Noncontrolling Interests in Subsidiaries		4	1	(4,036)
Net (Loss) Income Attributable to SEACOR Marine Holdings Inc.	$ (5,829)	$ (18,081)	$ 48,982	$ (40,099)
Net Earnings (Loss) Per Common Share from Continuing Operations:
Basic	$ (0.23)	$ (0.79)	$ 1.03	$ (1.64)
Diluted	(0.23)	(0.79)	1.02	(1.64)
Net Earnings (Loss) Per Share from Discontinued Operations:
Basic		0.07	0.90	0.01
Diluted		0.07	0.90	0.01
Net Earnings (Loss) per Share:
Basic	(0.23)	(0.72)	1.93	(1.63)
Diluted	$ (0.23)	$ (0.72)	$ 1.92	$ (1.63)
Weighted Average Common Stock and Warrants Outstanding:
Basic	25,515,569	24,989,977	25,419,303	24,611,666
Diluted	25,515,569	24,989,977	25,430,762	24,611,666

Unaudited Condensed Consolida_2

Unaudited Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Net (Loss) Income	$ (5,829)	$ (18,077)	$ 48,983	$ (44,135)
Other Comprehensive (Loss) Income:
Foreign currency translation (losses) gains	(504)	2,068	3,818	(385)
Derivative losses on cash flow hedges	(54)	(82)	(22)	(2,028)
Other comprehensive income (loss)	(63)	2,161	4,254	(1,928)
Comprehensive (Loss) Income	(5,892)	(15,916)	53,237	(46,063)
Comprehensive Income (Loss) Attributable to Noncontrolling Interests in Subsidiaries		4	1	(4,036)
Comprehensive (Loss) Income attributable to SEACOR Marine Holdings Inc.	(5,892)	(15,920)	53,236	(42,027)
Interest Expense
Other Comprehensive (Loss) Income:
Reclassification of derivative gains (losses) on cash flow hedges	415	457	1,245	964
Equity Method Investments1
Other Comprehensive (Loss) Income:
Reclassification of derivative gains (losses) on cash flow hedges	$ 80	$ (282)	$ (787)	$ (479)

Unaudited Condensed Consolida_3

Unaudited Condensed Consolidated Statements of Comprehensive Income (Loss) (Parenthetical)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Reclassification of derivative losses on cash flow hedges to equity in earnings	50.00%	50.00%	50.00%	50.00%

Unaudited Condensed Consolida_4

Unaudited Condensed Consolidated Statements of Changes In Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Gain (Loss) [Member]	Non-Controlling Interests In Subsidiaries [Member]
Balance at Dec. 31, 2019	$ 478,924	$ 219	$ 429,318	$ (669)	$ 27,076	$ 1,548	$ 21,432
Balance (in shares) at Dec. 31, 2019		21,881,487		47,187
Issuance of Common Stock	3,358	$ 9	3,349
Forfeiture of employee share awards (in shares)		(8,182)
Restricted stock grants	3	$ 3
Restricted stock grants (in shares)		289,452
Amortization of employee share awards	3,210		3,210
Exercise of Warrants	2	$ 3		$ (1)
Exercise of Warrants (in shares)		338,320		354
Restricted stock vesting	(178)			$ (178)
Restricted stock vesting (in shares)		(25,743)		25,743
Director share awards	755	$ 1	754
Director share awards (in shares)		59,900
Acquisition of consolidated joint venture	(3,357)		13,689				(17,046)
Acquisition of consolidated joint venture (in shares)		900,000
Net (loss) income	(44,135)				(40,099)		(4,036)
Other comprehensive loss	(1,928)					(1,928)
Balance at Sep. 30, 2020	436,654	$ 235	450,320	$ (848)	(13,023)	(380)	350
Balance (in shares) at Sep. 30, 2020		23,435,234		73,284
Balance at Jun. 30, 2020	451,364	$ 232	449,116	$ (847)	5,058	(2,541)	346
Balance (in shares) at Jun. 30, 2020		23,096,914		72,930
Amortization of employee share awards	1,204		1,204
Exercise of Warrants	2	$ 3		$ (1)
Exercise of Warrants (in shares)		338,320		354
Net (loss) income	(18,077)				(18,081)		4
Other comprehensive loss	2,161					2,161
Balance at Sep. 30, 2020	436,654	$ 235	450,320	$ (848)	(13,023)	(380)	350
Balance (in shares) at Sep. 30, 2020		23,435,234		73,284
Balance at Dec. 31, 2020	$ 401,836	$ 235	451,179	$ (848)	(51,839)	2,790	319
Balance (in shares) at Dec. 31, 2020	23,504,050	23,430,766		73,284
Forfeiture of employee share awards (in shares)		(5,250)
Restricted stock grants	$ 8	$ 8
Restricted stock grants (in shares)		815,550
Amortization of employee share awards	3,759		3,759
Restricted stock vesting	$ (272)			$ (272)
Restricted stock vesting (in shares)	(54,454)	(54,454)		54,454
Director share awards	$ 437	$ 2	435
Director share awards (in shares)		189,030
Sale of Windcat Workboats	(4,202)				(4,202)
Net (loss) income	48,983				48,982		1
Other comprehensive loss	4,254					4,254
Balance at Sep. 30, 2021	$ 454,803	$ 245	455,373	$ (1,120)	(7,059)	7,044	320
Balance (in shares) at Sep. 30, 2021	24,503,380	24,375,642		127,738
Balance at Jun. 30, 2021	$ 459,401	$ 245	454,079	$ (1,120)	(1,230)	7,107	320
Balance (in shares) at Jun. 30, 2021		24,380,892		127,738
Forfeiture of employee share awards (in shares)		(5,250)
Amortization of employee share awards	1,294		1,294
Net (loss) income	(5,829)				(5,829)
Other comprehensive loss	(63)					(63)
Balance at Sep. 30, 2021	$ 454,803	$ 245	$ 455,373	$ (1,120)	$ (7,059)	$ 7,044	$ 320
Balance (in shares) at Sep. 30, 2021	24,503,380	24,375,642		127,738

Unaudited Condensed Consolida_5

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020
Cash Flows from Continuing Operating Activities:
Net Income (Loss)		$ 48,983	$ (44,449)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization		43,197	41,920
Deferred financing costs amortization		769	841
Stock-based compensation expense		3,922	3,787
Debt discount amortization		5,252	4,755
Bad debt recoveries		278	376
(Gain) Loss from equipment sales, retirements or impairments		(20,436)	15,792
Gain on the Sale of Windcat Workboats		(22,756)
Gain from return of investments in 50% or less owned companies		(9,442)
Gain on Debt Extinguishment		(62,749)
Derivative gains		(387)	(5,204)
Interest on Finance Lease		3
Cash settlement payments on derivative transactions, net		(1,747)	(890)
Currency losses		878	8
Deferred income taxes		7,641	2,512
Equity Earnings		(10,584)	(1,518)
Dividends received from equity investees		4,515	2,117
Changes in Operating Assets and Liabilities:
Accounts receivables		23,594	(37,833)
Other assets		1,457	5,925
Accounts payable and accrued liabilities		(7,444)	(15,536)
Net cash provided by (used in) operating activities		4,944	(27,397)
Cash Flows from Continuing Investing Activities:
Purchases of property and equipment		(6,560)	(18,308)
Proceeds from disposition of property and equipment		30,137	20,674
Construction reserve funds utilized			9,148
Construction reserve funds transferred to short-term cash			3,745
Purchase of subsidiary from joint venture			(8,445)
Proceeds from sale of Windcat Workboats, net of transaction costs and cash sold	[1]	38,715
Investments in and advances to 50% or less owned companies		(736)	(958)
Excess distributions from equity investees		9,442
Principal payments on notes due from equity investees		3,975	490
Net cash provided by investing activities		74,973	6,346
Cash Flows from Continuing Financing Activities:
Payments on long-term debt		(72,143)	(16,821)
Payments on debt extinguishment cost		(755)	(1)
Payments on finance lease		(21)
Proceeds from exercise of warrant options			2
Issuance of stock		10
Net cash used in financing activities		(72,909)	(16,820)
Effects of Exchange Rate Changes on Cash and Cash Equivalents		(21)	(949)
Net Increase (Decrease) in Cash, Restricted Cash and Cash Equivalents		6,987	(38,820)
Cash Flows from Discontinued Operations:
Operating Activities		(171)	6,347
Investing Activities		0	(6,882)
Financing Activities		0	941
Effects of Exchange Rate Changes on Cash, Restricted Cash and Cash Equivalents			(102)
Net (Decrease) Increase in Cash, Restricted Cash and Cash Equivalents on Discontinued Operations		(171)	304
Net Increase (Decrease) in Cash, Restricted Cash and Cash Equivalents		6,816	(38,516)
Cash, Restricted Cash and Cash Equivalents, Beginning of Period		39,538	87,047
Cash, Restricted Cash and Cash Equivalents, End of Period		46,354	48,531
Supplemental disclosures:
Cash paid for interest, excluding capitalized interest		(15,231)	(15,387)
Income taxes refunded, net		32,759	456
Noncash Investing and Financing Activities:
Increase in property, plant and equipment related to an acquisition			142,282
Decrease in joint venture investments related to an acquisition			22,222
Increase in long-term debt related to an acquisition			75,569
Increase in long-term debt related to asset purchases		6,500	21,252
Decrease in debt related to debt settlement		(62,749)
Decrease in capital expenditures in accounts payable and accrued liabilities		$ (10,379)	$ (5,444)
[1]	Refer to Note 2. Equipment Acquisitions and Dispositions for a reconciliation of the cash received from the sale of Windcat Workboats

Basis of Presentation and Accou

Basis of Presentation and Accounting Policies	9 Months Ended
	Sep. 30, 2021
Basis Of Presentation And Accounting Policies [Abstract]
Basis of Presentation and Accounting Policies	1. The condensed consolidated financial statements include the accounts of SEACOR Marine Holdings Inc. and its consolidated subsidiaries (the “Company”). In the opinion of management, all adjustments (consisting of normal recurring adjustments) have been made to fairly present the unaudited condensed consolidated financial statements for the periods indicated. Results of operations for the interim periods presented are not necessarily indicative of operating results for the full year or any future periods. Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) have been condensed or omitted. These condensed consolidated financial statements should be read in conjunction with the Company’s financial statements and related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 (the “2020 Annual Report”). Unless the context otherwise indicates, any reference in this Quarterly Report on Form 10-Q to the “Company” refers to SEACOR Marine Holdings Inc. and its consolidated subsidiaries, and any reference in this Quarterly Report on Form 10-Q to “SEACOR Marine” refers to SEACOR Marine Holdings Inc. without its consolidated subsidiaries. The outbreak of the novel coronavirus (“COVID-19”) has caused significant disruptions and volatility in the global economy and marketplace. There remains continuing uncertainty regarding the length and severity of the impact of COVID-19 on the economy, in general, and the energy industry, in particular, each of which has a significant effect on the outlook for the Company’s business. The decrease in oil and natural gas prices experienced at the beginning stages of the COVID-19 pandemic led to a decrease in the demand for the Company’s products and services. Although the underlying commodity prices supporting such demand have recovered substantially, the risk of continued volatility in the commodity prices remains. A prolonged period of severely depressed oil and natural gas prices compared to historic averages could have a material adverse effect on the business. Recently Adopted Accounting Standards. On December 18, 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. The adoption of the standard by the Company did not have a material impact on its consolidated financial position or on its results of operations and cash flows. Recently Issued Accounting Standards On October 29, 2020, the FASB issued ASU 2020-10, Codification Improvements: Amendments that improve the consistency of the Codification by including all disclosure guidance in the appropriate Disclosure section. The guidance was effective for annual periods beginning after December 15, 2020, and interim periods within the annual periods beginning after December 15, 2022. The Company has not yet determined the impact adoption of the standard will have on the disclosures included herein. On August 5, 2020, the FASB issued ASU 2020-06, Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity, which simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity’s own equity. The guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2021. While early adoption is permitted, the Company has determined it will not early adopt the standards. 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 March 12, 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides temporary optional guidance to ease the potential burden in accounting for reference rate reform. The new guidance provides optional expedients and exceptions for applying generally accepted accounting principles to contract modifications and hedging relationships, subject to meeting certain criteria, that reference LIBOR or another reference rate expected to be discontinued. The ASU is intended to help stakeholders during the global market-wide reference rate transition period. Therefore, it will be in effect for a limited time through December 31, 2022. As of September 30, 2021, the reference rates for the Company’s existing debt and interest rate swaps have not changed as a result of any such amendment. The Company will continue to monitor changes to reference rates in applicable agreements and adopt the standard as needed. Critical Accounting Policies. 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 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 net income (loss) as equity in earnings (losses) 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 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. Such estimates include those related to deferred revenues, allowance for credit loss accounts, useful lives of property and equipment, impairments, income tax provisions and certain accrued liabilities. Actual results could differ from estimates and those differences may be material. Revenue Recognition . Revenue is recognized when (or as) the Company transfers promised goods or services to its customers in amounts that reflect the consideration to which the Company expects to be entitled to in exchange for those goods or services, which occurs when (or as) the Company satisfies its contractual obligations and transfers over control of the promised goods or services to its customers. The Company recognizes revenue net of sales taxes based on its estimates of the consideration the Company expects to receive. Costs to obtain or fulfill a contract are expensed as incurred. 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. Contract or charter durations may range from several days to several years. Charters vary in length from short-term to multi-year periods, many with cancellation clauses and without early termination penalties. As a result of options and frequent renewals, the stated duration of charters may have little correlation with the length of time the vessel is contracted to provide services to a particular customer. The Company also 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 other current liabilities in the accompanying consolidated balance sheets, for the nine months ended September 30, 2021 and nine months ended September 30, 2020 were as follows (in thousands): 2021 2020 Balance at beginning of period $ 3,307 $ 4,755 Revenues deferred during the period 490 6 Revenues recognized during the period (2,627 ) (2,774 ) Balance at end of period $ 1,170 $ 1,987 As of September 30, 2021, the Company had deferred revenues of $1.2 million primarily comprised of $0.7 million related to the time charter of offshore support vessels to customers from which collections were not reasonably assured, $0.3 million of prepaid charter modification and reservation fees and $0.2 million related to the demobilization of an offshore support vessel. As of September 30, 2021, the Company recognized deferred revenues of $2.0 million of prepaid vessel management fees on completion of management contract. Cash and 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 from current construction reserve funds (“CRF”) is also classified as cash and cash equivalents. There was no balance in current CRF as of September 30, 2021. For the year ended December 31, 2020, the current CRF balance was $4.2 million. Trade and Other Receivables. Customers are primarily major integrated national and international oil companies and large independent oil and natural gas exploration and production 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. The Company routinely reviews its receivables and makes provisions for the 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 are deemed uncollectible and are removed from accounts receivable and the allowance for credit losses when collection efforts have been exhausted. 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 assets 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 September 30, 2021, the estimated useful life (in years) of the Company’s new Offshore Support Vessels was 20 years. 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. During the nine months ended September 30, 2021 and 2020 capitalized interest totaled $0.3 million and $0.7 million, respectively. Impairment of Long-Lived Assets. The Company performs an impairment analysis of long-lived assets used in operations, including intangible assets, 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. Market conditions caused by COVID-19, including decreased global demand for oil and gas as well as the effect the pandemic has had on SEACOR Marine’s stock price, caused a triggering event for the nine months ended September 30, 2021 and 2020 to occur requiring the Company to test its assets for impairment. For the nine months ended September 30, 2021, the Company did not record an impairment on any owned or leased-in vessels. For the nine months ended September 30, 2020, the Company recorded impairment charges of $3.9 million related to four owned liftboats, $7.4 million related to two leased-in liftboats, and $1.2 million related to one specialty vessel due to a reduced sales price for the vessel. Estimated fair values for the Company’s owned vessels were established by independent appraisers based on researched market information, replacement cost information, and other data. For vessel classes and individual vessels with indicators of impairment as of September 30, 2021, 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 and the effect COVID-19 has had on the timing of an estimated market recovery in the offshore oil and natural gas markets and upon any such recovery, the timing and cost of reactivating cold-stacked vessels. If market conditions decline further, 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 have indicators of impairment and are deemed not recoverable through future operations, we determine 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% 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. During the nine months ended September 30, 2021 and 2020, the Company did not recognize any impairment charges related to its 50% or less owned companies. Income Taxes. During the nine months ended September 30, 2021, the Company’s effective income tax rate of 24.56% was primarily due to foreign taxes not creditable against U.S. income taxes offset by the impact of foreign sourced income not subject to U.S. income taxes. For the nine months ended September 30, 2020, the Company’s effective income tax rate of 34.97% was primarily due to taxes provided on income attributable to noncontrolling interest, foreign sourced income not subject to U.S. income taxes, foreign taxes not creditable against U.S. income taxes, and an adjustment for the acquisition of the remaining minority membership interest in a consolidated subsidiary. Accumulated Other Comprehensive Income (Loss). The components of accumulated other comprehensive loss were as follows (in thousands): SEACOR Marine Holdings Inc. Stockholders’ Equity Foreign Currency Translation Adjustments Derivative Losses on Cash Flow Hedges, net Total Other Comprehensive Loss December 31, 2020 $ 6,797 $ (4,007 ) $ 2,790 Other comprehensive loss 3,818 436 4,254 Balance as of September 30, 2021 $ 10,615 $ (3,571 ) $ 7,044 Earnings ( Basic earnings/loss per share of Common Stock of the Company is computed based on the weighted average number 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 Convertible Senior Notes (as defined in “Note 4. Long-Term Debt”) unless anti-dilutive. The Convertible Senior Notes are currently convertible into 2,907,500 shares of Common Stock (“Convertible Senior Note Shares”). For the three and nine months ended September 30, 2021, diluted earnings per share of Common Stock excluded 2,907,500 of the Convertible Senior Note Shares as the effect of their inclusion in the computation would be anti-dilutive. For the three and nine months ended September 30, 2020, diluted earnings/loss per share of Common Stock excluded 2,907,500 of Convertible Senior Note Shares as the effect of their inclusion in the computation would be anti-dilutive. The number of Convertible Senior Note Shares excluded from the calculation of diluted earnings per share was incorrectly reported in certain prior periods as 2,183,708. This number of shares was adjusted in the period ended June 30, 2021 following revisions to the calculation. In addition, for the nine months ended September 30, 2021, diluted earnings/loss per share of Common Stock included 11,459 shares of restricted stock, as their inclusion in the computation would be dilutive. For the three months ended September 30, 2021 and September 30, 2020 diluted earnings/loss per share of Common Stock excluded 1,131,599 and 469,964 shares of restricted stock, respectively, and for the nine months ended September 30, 2021 and September 30, 2020 diluted earnings/loss per share of Common Stock excluded 1,120,140 and 469,964 shares of restricted stock, respectively, as their inclusion in the computation would be anti-dilutive. For the three and nine months ended September 30, 2021 and September 30, 2020 diluted earnings/loss per share of Common Stock excluded 1,061,357 and 1,120,541 shares of stock, respectively, issuable upon exercise of outstanding stock options as the effect of their inclusion in the computation would be anti-dilutive.

Equipment Acquisitions and Disp

Equipment Acquisitions and Dispositions	9 Months Ended
	Sep. 30, 2021
Property Plant And Equipment [Abstract]
Equipment Acquisitions and Dispositions	2. EQUIPMENT ACQUISITIONS AND DISPOSITIONS During the nine months ended September $6.6 September During the nine months ended September Company sold one PSV, three FSVs and set off $22.5 million of debt under the FGUSA Credit Facility (as defined and described in Note 4 Long-Term Debt) with hull and machinery insurance proceeds for the liftboat SEACOR Power of $25.0 million, During the nine months ended September 30, 2020, the Company sold two anchor handling towing supply (“AHTS”) vessels and one specialty vessel previously removed from service, four FSVs, one specialty vessel, one vessel under construction and other equipment for $21.6 million in consideration ($20.7 million cash and $0.9 million in previously received deposits) and gains of $1.2 million. As of January 12, 2021, the Company recognized a gain on the sale of Windcat Workboats Holdings Ltd. (“Windcat Workboats”) of approximately $22.8 million, 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 See “Note 12. Discontinued Operations” for additional information on the sale of Windcat Workboats.

Investments, at Equity, and Adv

Investments, at Equity, and Advances to 50% or Less Owned Companies	9 Months Ended
	Sep. 30, 2021
Schedule Of Investments [Abstract]
Investments, at Equity, and Advances to 50% or Less Owned Companies	3. COMPANIES Investments, at equity, and advances to 50% or less owned companies as of September 30, 2021 and December 31, 2020 were as follows (in thousands): Ownership 2021 2020 MexMar 49.0 % $ 57,506 $ 50,037 OSV Partners (1) 30.4 % 7,592 9,094 SEACOR Marlin 49.0 % 7,844 7,979 MEXMAR Offshore (2) 49.0 % — 1,960 Offshore Vessel Holdings 49.0 % 2,203 2,388 Other 20.0% - 50.0 % 2,281 3,850 $ 77,426 $ 75,308 (1 ) The Company owns 66.7% of the General Partner and 29.7% of the limited partnership interest of OSV Partners. ( 2) This joint venture holds the investment in UP Offshore.

Long Term Debt

Long Term Debt	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Long Term Debt	4 . The Company’s long-term debt obligations as of September 30, 2021 and December 31, 2020 were as follows (in thousands): September 30, 2021 December 31, 2020 Recourse Long-term debt ( 1) Convertible Senior Notes $ 125,000 $ 125,000 SEACOR Marine Foreign Holdings Credit Facility 89,720 100,750 Sea-Cat Crewzer III Term Loan Facility 19,178 21,653 SEACOR Offshore Delta (f/k/a SEACOSCO) Acquisition Debt 18,705 19,705 SEACOR Delta (f/k/a SEACOSCO) Shipyard Financing 88,649 95,317 SEACOR Alpine Shipyard Financing 30,132 31,103 SEACOR 88/888 Term Loan 5,500 5,500 Tarahumara Shipyard Financing 6,500 — Total recourse Long-term debt 383,384 399,028 Non-recourse Long-term debt ( 2) Falcon Global USA Term Loan Facility — 102,349 Falcon Global USA Revolver — 15,000 SEACOR 88/888 Term Loan 5,500 5,500 Total non-recourse Long-term debt 5,500 122,849 Total principal due for long-term debt 388,884 521,877 Current portion due within one year (28,875 ) (32,377 ) Unamortized debt discount (35,012 ) (44,864 ) Deferred financing costs (3,356 ) (4,126 ) Long-term debt, less current portion $ 321,641 $ 440,510 (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) Non-recourse debt represents debt issued by the Company’s Consolidated Subsidiaries with no recourse to SEACOR Marine or its other non-debtor 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. As of September 30, 2021, the Company was in compliance with all debt covenants and lender requirements. Tarahumara Shipyard Financing . On July 9, 2021, SEACOR Marine LLC (“SMLLC”), an indirect subsidiary of SEACOR Marine, took delivery of the vessel named SEACOR Tarahumara, a 2021 new-build 221’ 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 $6.5 million. This term loan matures in 2025 with interest-only payments for the first year, and then the loan fully amortizes on a straight line basis over the remaining term. The term loan bears interest at a fixed 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”). Falcon Global. On June 10, 2021, SEACOR Marine, Falcon Global USA LLC, an indirect subsidiary of SEACOR Marine (“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 provides a guarantee of certain limited obligations of FGUSA under the FGUSA Credit Facility (as amended, the “FGUSA Obligation Guaranty”). As of June 10, 2021, there was $117.3 million of principal outstanding under the FGUSA Credit Facility. Under the terms of the Conditional Payoff Agreement, the $ 117.3 million of principal outstanding under the FGUSA Credit Facility was deemed satisfied in full following the payment to the lenders of a total of $ 50.0 million comprised of (i) $ 25.0 million paid by the Company at the signing of the Conditional Payoff Agreement, (ii) $ 22.5 million of hull and machinery insurance proceeds received by the lenders on June 18, 2021 in respect of the SEACOR Power incident and (iii) $ 2.5 million paid by the Company on June 24, 2021 ( the $ 2.5 million was subsequently reimbursed to the Company on June 29, 2021 from hull and machinery insurance proceeds). All payments required for the extinguishment of the debt pursuant to the Conditional Payoff Agreement were completed during the second quarter of 2021. Following the final payment on June 24, 2021, the FGUSA Credit Facility terminated, and the mortgages and security arrangements were released with respect to the nine liftboats securing the obligations under the FGUSA Credit Facility. 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 As of September September $2.44 Letters of Credit . As of September 30, 2021, the Company had outstanding letters of credit of $1.4 million securing lease obligations, labor and performance guaranties.

Leases

Leases	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Leases	5. LEASES As of September 30, 2021, the Company leased-in two anchor handling towing supply (“AHTS”) vessels and one As of September 30, 2021, future minimum payments for leases for the remainder of 2021 and the years ended December 31, noted below, were as follows (in thousands): Operating Leases Finance Leases Remainder of 2021 $ 1,114 $ 9 2022 583 36 2023 527 36 2024 451 37 2025 515 6 Years subsequent to 2025 4,073 — 7,263 124 Interest component (1,994 ) (8 ) 5,269 116 Current portion of long-term lease liabilities 1,269 32 Long-term lease liabilities $ 4,000 $ 84 For the nine months ended September 30, 2021 and September 30, 2020 the components of lease expense were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Operating lease cost $ 875 $ 1,030 $ 2,730 $ 5,305 Finance lease cost: Amortization of finance lease assets (1) 9 3 19 3 Interest on finance lease liabilities (2) 1 — 2 — Short-term lease costs 234 170 691 422 $ 1,119 $ 1,203 $ 3,442 $ 5,730 (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 nine months ended September 30, 2021, supplemental cash flow information related to leases was as follows (in thousands): 2021 Operating cash outflows from operating leases (6,365 ) Financing cash outflows from finance leases (21 ) Right-of-use assets obtained for operating lease liabilities 955 Right-of-use assets obtained for finance lease liabilities — For the nine months ended September 30, 2021, other information related to leases was as follows: 2021 Weighted average remaining lease term, in years - operating leases 12.6 Weighted average remaining lease term, in years - finance leases 3.4 Weighted average discount rate - operating leases 5.7 % Weighted average discount rate - finance leases 4.0 %

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	6 . The following table reconciles the difference between the statutory federal income tax rate for the Company and the effective income tax rate on continuing operations for the nine months ended September 30, 2021: Statutory rate 21.00 % Foreign withholding tax 8.89 % Foreign earnings not subject to U.S. Income Tax (5.47 )% Other 0.14 % 24.56 % On June 26, 2020, the Company entered into a Tax Refund and Indemnification Agreement (the “Tax Refund Agreement”) with SEACOR Holdings Inc. (“SEACOR Holdings”), the Company’s former parent company. The Tax Refund Agreement enabled the Company to utilize net operating losses (“NOLs”) 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 Coronavirus Aid, Relief, and Economic Security Act (“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 Internal Revenue Service (“IRS”) in respect of refund payment delays), of which $12.5 million was received prior to March 31, 2021 and the remaining $19.8 million was received in April 2021.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Strategies	9 Months Ended
	Sep. 30, 2021
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Strategies	7 . Derivative instruments are classified as either assets or liabilities based on their individual fair values. The fair values of the Company’s derivative instruments were as follows (in thousands): September 30, 2021 December 31, 2020 Derivative Asset Derivative Liability Derivative Asset Derivative Liability Derivatives designated as hedging instruments: Interest rate swap agreements (cash flow hedges) $ — $ 2,476 $ — $ 3,698 — 2,476 — 3,698 Derivatives not designated as hedging instruments: Forward Exchange Contract — — — 893 Conversion option liability on Convertible Senior Notes — 5 — 2 $ — $ 5 $ — $ 895 Economic Hedges. The Company enters and settles 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 twelve to eighteen months. During the nine months ended September 30, 2021, the Company recognized gains of $0.4 million on these contracts which were recognized concurrently in earnings. As of September 30, 2021, the Company no longer has open forward currency exchange contracts. Cash Flow Hedges. The Company and certain of its 50% or less owned companies have interest rate swap agreements designated as cash flow hedges. By entering into these interest rate swap agreements, the Company and its 50% or less owned companies have converted the variable LIBOR component of certain of their outstanding borrowings to a fixed interest rate. The Company recognized gains on derivative instruments designated as cash flow hedges as a component of other comprehensive income of $1.6 million for the nine months ended September 30, 2021, and losses of $1.1 million for the nine months ended September 30, 2020 as a component of other comprehensive loss. As of September 30, 2021, the interest rate swaps held by the Company and certain of the Company’s 50% or less owned companies were as follows • SEACOR Marine Foreign Holdings Inc., an indirect wholly-owned subsidiary of SEACOR Marine (“ SMFH”) has an interest rate swap agreement maturing in 2023 that calls for SMFH to pay a fixed rate of interest of 3.32% per annum on the amortized notional value of $7.1 million and receive a variable interest rate based on LIBOR on the amortized notional value; • SMFH has an interest rate swap agreement maturing in 2023 that calls for SMFH to pay a fixed rate of interest of 3.195% per annum on the amortized notional value of $38.9 million and receive a variable interest rate based on LIBOR on the amortized notional value; • SEACOR 88 LLC and SEACOR 888 LLC, both indirect wholly-owned subsidiaries of SEACOR Marine (collectively, “SEACOR 88/888”), have an interest rate swap agreement maturing in 2023 that calls for SEACOR 88/888 to pay a fixed rate of interest of 3.175% per annum on the amortized notional value of $5.5 million and receive a variable interest rate based on LIBOR on the amortized notional value; and • Mantenimiento Express Maritimo, S.A.P.I. de C.V. (“MexMar”), in which the Company has a 49% noncontrolling interest, has five interest rate swap agreements with maturities in 2023 that call for MexMar to pay fixed rates of interest ranging from 1.71% to 2.10% per annum on the aggregate amortized notional value of $60.7 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value. Other Derivative Instruments. The Company recognized gains (losses) on derivative instruments not designated as hedging instruments for the nine months ended September 30, 2021 and September 30, 2020 as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Conversion option liability on Convertible Senior Notes $ 3 $ 5 $ (3 ) $ 5,204 Forward currency exchange, option, and future contracts — — 390 — $ 3 $ 5 $ 387 $ 5,204 The conversion option liability relates to the bifurcated embedded conversion option in the Convertible Senior Notes issued to investment funds managed and controlled by The Carlyle Group (see “Note 8. Fair Value Measurements”).

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	8 . 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 Level Level Level The Company’s financial assets and liabilities as of September 30, 2021 and December 31, 2020 that are measured at fair value on a recurring basis were as follows (in thousands): September 30, 2021 Level 1 Level 2 Level 3 LIABILITIES Derivative instruments — 2,476 — Conversion Option Liability on Convertible Senior Notes — — 5 December 31, 2020 LIABILITIES Derivative instruments — 4,591 — Conversion Option Liability on Convertible Senior Notes — — 2 Level 3 . The fair value of the conversion option liability embedded in the Convertible Senior Notes is estimated with significant inputs that are both observable and unobservable in the market and therefore is considered a Level 3 fair value measurement. The Company used a binomial lattice model that assumes the holders will maximize their value by finding the optimal decision between redeeming at the redemption price or converting into shares of Common Stock. This model estimates the fair value of the conversion option as the differential in the fair value of the notes including the conversion option compared with the fair value of the notes excluding the conversion option. The significant observable inputs used in the fair value measurement include the price of Common Stock and the risk-free interest rate. The significant unobservable inputs are the estimated Company credit spread and Common Stock volatility, which were based on comparable companies in the transportation and energy industries. The estimated fair values of the Company’s other financial assets and liabilities as of September 30, 2021 and December 31, 2020 were as follows (in thousands): Estimated Fair Value September 30, 2021 Carrying Amount Level 1 Level 2 Level 3 ASSETS Cash, cash equivalents and restricted cash $ 46,354 $ 46,354 $ — $ — LIABILITIES Long-term debt, including current portion 350,515 — 358,988 — December 31, 2020 ASSETS Cash, cash equivalents and restricted cash $ 36,018 $ 36,018 $ — $ — LIABILITIES Long-term debt, including current portion 472,887 — 470,561 — 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 including the consideration of the COVID-19 pandemic that has caused significant volatility in U.S. and international markets, 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 nine months ended September 30, 2021, the Company recognized no impairment charges, and none of the Company’s property and equipment had a fair value based on ordinary liquidation value or indicative sales price. As of December 31, 2020, the Company had Level 2 fair values, determined based upon ordinary liquidation value, of $43.0 million on five liftboats.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. COMMITMENTS AND CONTINGENCIES As of September 30, 2021, the Company had unfunded capital commitments of $0.9 million for miscellaneous vessel equipment payable during 2022. The Company has indefinitely deferred an additional $9.4 million of orders with respect to one FSV that the Company had previously reported as unfunded capital commitments. In December 2015, the Brazilian Federal Revenue Office issued a tax-deficiency notice to Seabulk Offshore do Brasil Ltda, an indirect wholly-owned subsidiary of SEACOR Marine (“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. Recently, a local Brazilian law was 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$18.8 million based on a historical potential levy of R$12.87 million (USD $3.5 million and USD $2.4 million, respectively, based on the exchange rate as of September 30, 2021). As of September 30, 2021, SEACOR Holdings has guaranteed $0.8 million on behalf of the Company for performance obligations under sale-leaseback arrangements. Pursuant to the terms of the Tax Refund Agreement with SEACOR Holdings, as of September 30, 2021, $0.8 million of refunds remained in an account to be used solely to satisfy such obligations guaranteed by SEACOR Holdings. On April 13, 2021, the SEACOR Power, a liftboat owned by a subsidiary of the Company with nineteen individuals on board, capsized off the coast of Port Fourchon, Louisiana. The incident resulted in the death of several crew members, including the captain of the vessel. The incident also resulted in the constructive total loss of the SEACOR Power. The Company is responsible for the salvage operations related to the vessel and is coordinating these efforts with the U.S. Coast Guard. The salvage operations are currently ongoing and the Company expects salvage costs to be covered by insurance proceeds. The capsizing of the SEACOR Power garnered significant attention from the media as well as local, state and federal politicians. The National Transportation Safety Board (“NTSB”) and the U.S. Coast Guard are currently investigating the incident to determine the cause of the incident and the Company is fully cooperating with the investigation in all respects and continues to gather information about the incident. It is expected that the joint NTSB and U.S. Coast Guard investigation will take a significant period of time to complete, possibly as much as two years or longer. Numerous civil lawsuits have been filed against the Company and other third parties by the family members of deceased crew members and the surviving crew members employed by the Company or by the third parties. On June 2, 2021, the Company filed a Limitation of Liability Act complaint in federal court in the Eastern District of Louisiana (“Limitation Action”), which has the effect of enjoining all existing civil lawsuits and requiring the plaintiffs to file their claims relating to the capsizing of the SEACOR Power in the Limitation Action. There is significant uncertainty in the amount and timing of costs and potential liabilities relating to the incident involving the SEACOR Power, the impact the incident will have on the Company’s reputation and the resulting possible impact on the Company’s business. In the normal course of its business, the Company becomes involved in various other 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 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 September 30, 2021, all invoices 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. The MNRPF indicated that the investigations into these issues were at an early stage and remained ongoing, and that further updates would be provided as significant developments arise. Should such additional liabilities require the MNRPF to collect additional funds from participating employers, it is possible that the Company will be invoiced for a portion of such funds and recognize payroll related operating expenses in the periods invoices are received.

Stock Based Compensation

Stock Based Compensation	9 Months Ended
	Sep. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Based Compensation	10. STOCK BASED COMPENSATION Transactions in connection with the Company’s Equity Incentive Plans during the nine months ended September 30, 2021 were as follows: Restricted Stock Activity: Outstanding as of December 31, 2020 436,714 Granted (1) 902,214 Vested (202,079 ) Forfeited (5,250 ) Outstanding as of September 30, 2021 1,131,599 Stock Option Activity: Outstanding as of December 31, 2020 1,120,541 Granted 12,500 Exercised — Forfeited (71,684 ) Outstanding as of September 30, 2021 1,061,357 (1) Excludes 157,455 grants of performance-based stock units that are not considered outstanding until such time that they become probable to vest. For the nine months ended September 30, 2021, the Company acquired for treasury 54,454 shares of Common Stock from its employees to cover their tax withholding obligations upon the lapsing of restrictions on share awards for an aggregate purchase price of $0.3 million. These shares were purchased in accordance with the terms of the Company’s 2017 Equity Incentive Plan and the Company’s 2020 Equity Incentive Plan.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Segment Information	11. SEGMENT INFORMATION The Company’s segment presentation and basis of measurement of segment profit or loss are as previously described in the 2020 Annual Report. Certain reclassifications of prior period information have been made to conform the current period’s reportable segment presentation as a result of the Company’s presentation of Discontinued Operations (see “Note 12. Discontinued Operations”). In prior periods Africa and Europe were reported as separate segments. Due to the sale of Windcat Workboats, the Company’s European operations are 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 following tables summarize the operating results, capital expenditures and assets of the Company’s reportable segments for the periods indicated (in thousands): United States (primarily Gulf of Mexico) Africa and Europe (2) Middle East and Asia Latin America Total For the Three Months Ended September 30, 2021 Operating Revenues: Time charter $ 5,289 $ 10,446 $ 13,417 $ 12,630 41,782 Bareboat charter — — — — — Other marine services 1,215 (429 ) 85 1,010 1,881 6,504 10,017 13,502 13,640 43,663 Direct Costs and Expenses: Operating: Personnel 2,428 3,147 5,849 3,627 15,051 Repairs and maintenance 1,266 1,540 1,610 2,120 6,536 Drydocking 239 337 156 39 771 Insurance and loss reserves 462 323 707 697 2,189 Fuel, lubes and supplies 259 1,631 777 1,017 3,684 Other 147 1,424 2,823 823 5,217 4,801 8,402 11,922 8,323 33,448 Direct Vessel Profit $ 1,703 $ 1,615 $ 1,580 $ 5,317 10,215 Other Costs and Expenses: Lease expense $ 621 $ 284 $ 377 $ (173 ) 1,109 Administrative and general 9,134 Depreciation and amortization 3,936 3,296 4,456 2,618 14,306 24,549 Gain on Asset Dispositions, Net 56 Operating Loss $ (14,278 ) United States (primarily Gulf of Mexico) Africa and Europe, Continuing Operations (2) Middle East and Asia Latin America Total For the Nine Months Ended September 30, 2021 Operating Revenues: Time charter $ 10,197 $ 32,385 $ 39,744 $ 35,220 117,546 Bareboat charter 1,163 — — — 1,163 Other marine services 2,488 (922 ) 476 2,223 4,265 13,848 31,463 40,220 37,443 122,974 Direct Costs and Expenses: Operating: Personnel 5,700 10,620 16,435 10,067 42,822 Repairs and maintenance 2,309 4,926 5,319 4,781 17,335 Drydocking 1,891 1,015 2,407 467 5,780 Insurance and loss reserves 1,912 1,108 1,870 1,918 6,808 Fuel, lubes and supplies 703 3,090 2,417 2,569 8,779 Other 448 4,075 4,010 2,313 10,846 12,963 24,834 32,458 22,115 92,370 Direct Vessel Profit $ 885 $ 6,629 $ 7,762 $ 15,328 30,604 Other Costs and Expenses: Lease expense $ 1,988 $ 910 $ 434 $ 89 3,421 Administrative and general 26,897 Depreciation and amortization 11,387 9,908 13,829 8,073 43,197 73,515 Gain on Asset Dispositions, Net 20,436 Operating Loss $ (22,475 ) As of September 30, 2021 Property and Equipment: Historical Cost 248,125 212,491 358,356 170,938 989,910 Accumulated Depreciation (122,437 ) (66,424 ) (85,054 ) (29,263 ) (303,178 ) $ 125,688 $ 146,067 $ 273,302 $ 141,675 $ 686,732 Total Assets (1) $ 149,286 $ 162,815 $ 274,324 $ 211,909 $ 798,334 (1) Total assets by region does not include corporate assets of $103.7 million as of September 30, 2021 . (2) In prior periods Africa and Europe were reported as separate segments. Due to the sale of Windcat Workboats, the Company’s European operations are 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 consolidated with Africa and reported as a consolidated segment and prior period information has been conformed to the new consolidated reporting segment. United States (primarily Gulf of Mexico) Africa and Europe (2) Middle East and Asia Latin America Total For the Three Months Ended September 30, 2020 Operating Revenues: Time charter $ 1,668 $ 10,861 $ 13,672 $ 8,621 $ 34,822 Bareboat charter 731 (55 ) — — 676 Other marine services 473 (255 ) 296 212 726 2,872 10,551 13,968 8,833 36,224 Direct Costs and Expenses: Operating: Personnel 2,481 3,407 5,171 2,342 13,401 Repairs and maintenance 338 1,158 1,564 704 3,764 Drydocking — 481 104 — 585 Insurance and loss reserves 778 398 451 138 1,765 Fuel, lubes and supplies 251 1,091 482 307 2,131 Other 85 773 1,771 444 3,073 3,933 7,308 9,543 3,935 24,719 Direct Vessel (Loss) Profit $ (1,061 ) $ 3,243 $ 4,425 $ 4,898 $ 11,505 Other Costs and Expenses: Lease expense $ 716 $ 429 $ 46 $ 9 $ 1,200 Administrative and general 8,885 Depreciation and amortization 4,961 3,785 4,379 1,708 14,833 24,918 Gain on Asset Dispositions and Impairments 233 Operating Loss, for Continuing Operations $ (13,180 ) United States (primarily Gulf of Mexico) Africa and Europe, Continuing Operations (2) Middle East and Asia Latin America Total For the Nine Months Ended September 30, 2020 Operating Revenues: Time charter $ 7,521 $ 37,927 $ 39,044 $ 16,268 $ 100,760 Bareboat charter 2,178 (55 ) — — 2,123 Other 1,628 (454 ) 1,230 529 2,933 11,327 37,418 40,274 16,797 105,816 Direct Costs and Expenses: Operating: Personnel 7,693 9,887 12,777 4,934 35,291 Repairs and maintenance 1,269 4,206 4,390 1,351 11,216 Drydocking 1,167 745 718 (114 ) 2,516 Insurance and loss reserves 1,267 1,295 1,220 312 4,094 Fuel, lubes and supplies 964 2,407 2,102 574 6,047 Other 257 2,017 3,273 872 6,419 12,617 20,557 24,480 7,929 65,583 Direct Vessel (Loss) Profit, from Continuing Operations $ (1,290 ) $ 16,861 $ 15,794 $ 8,868 $ 40,233 Other Costs and Expenses: Lease expense $ 3,595 $ 1,982 $ 123 $ 27 $ 5,727 Administrative and general 31,519 Depreciation and amortization 15,573 10,700 12,090 3,557 41,920 79,166 Loss on Asset Dispositions and Impairments (15,792 ) Operating Loss, for Continuing Operations $ (54,725 ) As of September 30, 2020 Property and Equipment: Historical Cost 258,710 262,809 365,049 109,802 996,370 Accumulated Depreciation (128,390 ) (65,520 ) (75,013 ) (11,545 ) (280,468 ) $ 130,320 $ 197,289 $ 290,036 $ 98,257 $ 715,902 Total Assets (1) $ 172,218 $ 231,211 $ 312,622 $ 175,164 $ 891,215 (1) Total assets by region does not include corporate assets of $119.2 million, and $46.8 million of discontinued operations as of September 30, 2020. (2) In prior periods Africa and Europe were reported as separate segments. Due to the sale of Windcat Workboats, the Company’s European operations are 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 consolidated with Africa and reported as a consolidated segment and prior period information has been conformed to the new consolidated reporting segment. The Company’s investments in 50% or less owned companies, which are accounted for under the equity method, also contribute to its consolidated results of operations. As of September 30, 2021, and 2020, the Company’s investments, at equity and advances to 50% or less owned companies in its other 50% or less owned companies were $77.4 million and $84.7 million, respectively. Equity in gains (losses) earnings of 50% or less owned companies for the nine months ended September 30, 2021 and 2020 were $10.6 million and $1.5 million, respectively.

Discontinued Operations

Discontinued Operations	9 Months Ended
	Sep. 30, 2021
Discontinued Operations And Disposal Groups [Abstract]
Discontinued Operations	12. DISCONTINUED OPERATIONS On January 12, 2021, the Company completed the sale of Windcat Workboats, which was previously classified as assets held for sale. Following the completion of the sale, the Company has no continuing involvement in this business, which is 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. 2 Equipment Acquisitions and Dispositions”). Summarized selected operating result of the Company’s assets related to Windcat Workboats, previously classified as held for sale were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Windcat Workboats Operating Revenues: Time charter $ — $ 8,764 $ 903 $ 21,923 Other revenue — 709 70 1,579 — 9,473 973 23,502 Costs and Expenses: Operating — 4,409 578 12,078 Direct Vessel Profit — 5,064 395 11,424 General and Administrative Expenses — 1,270 238 3,961 Lease Expense — 190 24 425 Depreciation — 1,780 — 5,007 — 3,240 262 9,393 Operating Income — 1,824 133 2,031 Other Income (Expense) Interest income — 16 2 43 Interest expense — (286 ) (39 ) (828 ) Foreign currency translation loss — 58 89 (951 ) — (212 ) 52 (1,736 ) Operating Loss Before Equity Earnings of 50% or Less Owned Companies, Net of Tax $ — $ 1,612 $ 185 $ 295 Income Tax Expense (Benefit) — 1 — (79 ) Operating Income Before Equity Earnings of 50% or Less Owned Companies $ — $ 1,611 $ 185 $ 374 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax — 155 (16 ) (60 ) Net Income from Discontinued Operations $ — $ 1,766 $ 169 $ 314

Basis of Presentation and Acc_2

Basis of Presentation and Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards. On December 18, 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. The adoption of the standard by the Company did not have a material impact on its consolidated financial position or on its results of operations and cash flows.
Recently Issued Accounting Standards	Recently Issued Accounting Standards On October 29, 2020, the FASB issued ASU 2020-10, Codification Improvements: Amendments that improve the consistency of the Codification by including all disclosure guidance in the appropriate Disclosure section. The guidance was effective for annual periods beginning after December 15, 2020, and interim periods within the annual periods beginning after December 15, 2022. The Company has not yet determined the impact adoption of the standard will have on the disclosures included herein. On August 5, 2020, the FASB issued ASU 2020-06, Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity, which simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity’s own equity. The guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2021. While early adoption is permitted, the Company has determined it will not early adopt the standards. 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 March 12, 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides temporary optional guidance to ease the potential burden in accounting for reference rate reform. The new guidance provides optional expedients and exceptions for applying generally accepted accounting principles to contract modifications and hedging relationships, subject to meeting certain criteria, that reference LIBOR or another reference rate expected to be discontinued. The ASU is intended to help stakeholders during the global market-wide reference rate transition period. Therefore, it will be in effect for a limited time through December 31, 2022. As of September 30, 2021, the reference rates for the Company’s existing debt and interest rate swaps have not changed as a result of any such amendment. The Company will continue to monitor changes to reference rates in applicable agreements and adopt the standard as needed.
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 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 net income (loss) as equity in earnings (losses) 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 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. Such estimates include those related to deferred revenues, allowance for credit loss accounts, useful lives of property and equipment, impairments, income tax provisions and certain accrued liabilities. Actual results could differ from estimates and those differences may be material.
Revenue Recognition	Revenue Recognition . Revenue is recognized when (or as) the Company transfers promised goods or services to its customers in amounts that reflect the consideration to which the Company expects to be entitled to in exchange for those goods or services, which occurs when (or as) the Company satisfies its contractual obligations and transfers over control of the promised goods or services to its customers. The Company recognizes revenue net of sales taxes based on its estimates of the consideration the Company expects to receive. Costs to obtain or fulfill a contract are expensed as incurred. 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. Contract or charter durations may range from several days to several years. Charters vary in length from short-term to multi-year periods, many with cancellation clauses and without early termination penalties. As a result of options and frequent renewals, the stated duration of charters may have little correlation with the length of time the vessel is contracted to provide services to a particular customer. The Company also 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 other current liabilities in the accompanying consolidated balance sheets, for the nine months ended September 30, 2021 and nine months ended September 30, 2020 were as follows (in thousands): 2021 2020 Balance at beginning of period $ 3,307 $ 4,755 Revenues deferred during the period 490 6 Revenues recognized during the period (2,627 ) (2,774 ) Balance at end of period $ 1,170 $ 1,987 As of September 30, 2021, the Company had deferred revenues of $1.2 million primarily comprised of $0.7 million related to the time charter of offshore support vessels to customers from which collections were not reasonably assured, $0.3 million of prepaid charter modification and reservation fees and $0.2 million related to the demobilization of an offshore support vessel. As of September 30, 2021, the Company recognized deferred revenues of $2.0 million of prepaid vessel management fees on completion of management contract.
Cash and Cash Equivalents	Cash and 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 from current construction reserve funds (“CRF”) is also classified as cash and cash equivalents. There was no balance in current CRF as of September 30, 2021. For the year ended December 31, 2020, the current CRF balance was $4.2 million.
Trade and Other Receivables	Trade and Other Receivables. Customers are primarily major integrated national and international oil companies and large independent oil and natural gas exploration and production 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. The Company routinely reviews its receivables and makes provisions for the 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 are deemed uncollectible and are removed from accounts receivable and the allowance for credit losses when collection efforts have been exhausted.
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 assets 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 September 30, 2021, the estimated useful life (in years) of the Company’s new Offshore Support Vessels was 20 years. 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. During the nine months ended September 30, 2021 and 2020 capitalized interest totaled $0.3 million and $0.7 million, respectively.
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, including intangible assets, 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. Market conditions caused by COVID-19, including decreased global demand for oil and gas as well as the effect the pandemic has had on SEACOR Marine’s stock price, caused a triggering event for the nine months ended September 30, 2021 and 2020 to occur requiring the Company to test its assets for impairment. For the nine months ended September 30, 2021, the Company did not record an impairment on any owned or leased-in vessels. For the nine months ended September 30, 2020, the Company recorded impairment charges of $3.9 million related to four owned liftboats, $7.4 million related to two leased-in liftboats, and $1.2 million related to one specialty vessel due to a reduced sales price for the vessel. Estimated fair values for the Company’s owned vessels were established by independent appraisers based on researched market information, replacement cost information, and other data. For vessel classes and individual vessels with indicators of impairment as of September 30, 2021, 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 and the effect COVID-19 has had on the timing of an estimated market recovery in the offshore oil and natural gas markets and upon any such recovery, the timing and cost of reactivating cold-stacked vessels. If market conditions decline further, 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 have indicators of impairment and are deemed not recoverable through future operations, we determine 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% 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. During the nine months ended September 30, 2021 and 2020, the Company did not recognize any impairment charges related to its 50% or less owned companies.
Income Taxes	Income Taxes. During the nine months ended September 30, 2021, the Company’s effective income tax rate of 24.56% was primarily due to foreign taxes not creditable against U.S. income taxes offset by the impact of foreign sourced income not subject to U.S. income taxes. For the nine months ended September 30, 2020, the Company’s effective income tax rate of 34.97% was primarily due to taxes provided on income attributable to noncontrolling interest, foreign sourced income not subject to U.S. income taxes, foreign taxes not creditable against U.S. income taxes, and an adjustment for the acquisition of the remaining minority membership interest in a consolidated subsidiary.
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss). The components of accumulated other comprehensive loss were as follows (in thousands): SEACOR Marine Holdings Inc. Stockholders’ Equity Foreign Currency Translation Adjustments Derivative Losses on Cash Flow Hedges, net Total Other Comprehensive Loss December 31, 2020 $ 6,797 $ (4,007 ) $ 2,790 Other comprehensive loss 3,818 436 4,254 Balance as of September 30, 2021 $ 10,615 $ (3,571 ) $ 7,044
Earnings (Loss) Per Share	Earnings ( Basic earnings/loss per share of Common Stock of the Company is computed based on the weighted average number 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 Convertible Senior Notes (as defined in “Note 4. Long-Term Debt”) unless anti-dilutive. The Convertible Senior Notes are currently convertible into 2,907,500 shares of Common Stock (“Convertible Senior Note Shares”). For the three and nine months ended September 30, 2021, diluted earnings per share of Common Stock excluded 2,907,500 of the Convertible Senior Note Shares as the effect of their inclusion in the computation would be anti-dilutive. For the three and nine months ended September 30, 2020, diluted earnings/loss per share of Common Stock excluded 2,907,500 of Convertible Senior Note Shares as the effect of their inclusion in the computation would be anti-dilutive. The number of Convertible Senior Note Shares excluded from the calculation of diluted earnings per share was incorrectly reported in certain prior periods as 2,183,708. This number of shares was adjusted in the period ended June 30, 2021 following revisions to the calculation. In addition, for the nine months ended September 30, 2021, diluted earnings/loss per share of Common Stock included 11,459 shares of restricted stock, as their inclusion in the computation would be dilutive. For the three months ended September 30, 2021 and September 30, 2020 diluted earnings/loss per share of Common Stock excluded 1,131,599 and 469,964 shares of restricted stock, respectively, and for the nine months ended September 30, 2021 and September 30, 2020 diluted earnings/loss per share of Common Stock excluded 1,120,140 and 469,964 shares of restricted stock, respectively, as their inclusion in the computation would be anti-dilutive. For the three and nine months ended September 30, 2021 and September 30, 2020 diluted earnings/loss per share of Common Stock excluded 1,061,357 and 1,120,541 shares of stock, respectively, issuable upon exercise of outstanding stock options as the effect of their inclusion in the computation would be anti-dilutive.

Basis of Presentation and Acc_3

Basis of Presentation and Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Basis Of Presentation 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 other current liabilities in the accompanying consolidated balance sheets, for the nine months ended September 30, 2021 and nine months ended September 30, 2020 were as follows (in thousands): 2021 2020 Balance at beginning of period $ 3,307 $ 4,755 Revenues deferred during the period 490 6 Revenues recognized during the period (2,627 ) (2,774 ) Balance at end of period $ 1,170 $ 1,987
Schedule of Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss). The components of accumulated other comprehensive loss were as follows (in thousands): SEACOR Marine Holdings Inc. Stockholders’ Equity Foreign Currency Translation Adjustments Derivative Losses on Cash Flow Hedges, net Total Other Comprehensive Loss December 31, 2020 $ 6,797 $ (4,007 ) $ 2,790 Other comprehensive loss 3,818 436 4,254 Balance as of September 30, 2021 $ 10,615 $ (3,571 ) $ 7,044

Equipment Acquisitions and Di_2

Equipment Acquisitions and Dispositions (Tables)	9 Months Ended
	Sep. 30, 2021
Property Plant And Equipment [Abstract]
Schedule of Gain on Sale of Windcat Workboats	As of January 12, 2021, the Company recognized a gain on the sale of Windcat Workboats Holdings Ltd. (“Windcat Workboats”) of approximately $22.8 million, 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)	9 Months Ended
	Sep. 30, 2021
Schedule Of Investments [Abstract]
Equity Method Investments	Investments, at equity, and advances to 50% or less owned companies as of September 30, 2021 and December 31, 2020 were as follows (in thousands): Ownership 2021 2020 MexMar 49.0 % $ 57,506 $ 50,037 OSV Partners (1) 30.4 % 7,592 9,094 SEACOR Marlin 49.0 % 7,844 7,979 MEXMAR Offshore (2) 49.0 % — 1,960 Offshore Vessel Holdings 49.0 % 2,203 2,388 Other 20.0% - 50.0 % 2,281 3,850 $ 77,426 $ 75,308 (1 ) The Company owns 66.7% of the General Partner and 29.7% of the limited partnership interest of OSV Partners. ( 2) This joint venture holds the investment in UP Offshore.

Long-term Debt (Tables)

Long-term Debt (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Schedule of Long-term Debt Obligations	The Company’s long-term debt obligations as of September 30, 2021 and December 31, 2020 were as follows (in thousands): September 30, 2021 December 31, 2020 Recourse Long-term debt ( 1) Convertible Senior Notes $ 125,000 $ 125,000 SEACOR Marine Foreign Holdings Credit Facility 89,720 100,750 Sea-Cat Crewzer III Term Loan Facility 19,178 21,653 SEACOR Offshore Delta (f/k/a SEACOSCO) Acquisition Debt 18,705 19,705 SEACOR Delta (f/k/a SEACOSCO) Shipyard Financing 88,649 95,317 SEACOR Alpine Shipyard Financing 30,132 31,103 SEACOR 88/888 Term Loan 5,500 5,500 Tarahumara Shipyard Financing 6,500 — Total recourse Long-term debt 383,384 399,028 Non-recourse Long-term debt ( 2) Falcon Global USA Term Loan Facility — 102,349 Falcon Global USA Revolver — 15,000 SEACOR 88/888 Term Loan 5,500 5,500 Total non-recourse Long-term debt 5,500 122,849 Total principal due for long-term debt 388,884 521,877 Current portion due within one year (28,875 ) (32,377 ) Unamortized debt discount (35,012 ) (44,864 ) Deferred financing costs (3,356 ) (4,126 ) Long-term debt, less current portion $ 321,641 $ 440,510 (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) Non-recourse debt represents debt issued by the Company’s Consolidated Subsidiaries with no recourse to SEACOR Marine or its other non-debtor 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 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

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Summary of Future Minimum Payments For Leases	As of September 30, 2021, future minimum payments for leases for the remainder of 2021 and the years ended December 31, noted below, were as follows (in thousands): Operating Leases Finance Leases Remainder of 2021 $ 1,114 $ 9 2022 583 36 2023 527 36 2024 451 37 2025 515 6 Years subsequent to 2025 4,073 — 7,263 124 Interest component (1,994 ) (8 ) 5,269 116 Current portion of long-term lease liabilities 1,269 32 Long-term lease liabilities $ 4,000 $ 84
Summary of Components of Leases Expense	For the nine months ended September 30, 2021 and September 30, 2020 the components of lease expense were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Operating lease cost $ 875 $ 1,030 $ 2,730 $ 5,305 Finance lease cost: Amortization of finance lease assets (1) 9 3 19 3 Interest on finance lease liabilities (2) 1 — 2 — Short-term lease costs 234 170 691 422 $ 1,119 $ 1,203 $ 3,442 $ 5,730 (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 nine months ended September 30, 2021, supplemental cash flow information related to leases was as follows (in thousands): 2021 Operating cash outflows from operating leases (6,365 ) Financing cash outflows from finance leases (21 ) Right-of-use assets obtained for operating lease liabilities 955 Right-of-use assets obtained for finance lease liabilities —
Summary of Other Information Related to Leases	For the nine months ended September 30, 2021, other information related to leases was as follows: 2021 Weighted average remaining lease term, in years - operating leases 12.6 Weighted average remaining lease term, in years - finance leases 3.4 Weighted average discount rate - operating leases 5.7 % Weighted average discount rate - finance leases 4.0 %

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
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 on continuing operations for the nine months ended September 30, 2021: Statutory rate 21.00 % Foreign withholding tax 8.89 % Foreign earnings not subject to U.S. Income Tax (5.47 )% Other 0.14 % 24.56 %

Derivative Instruments and He_2

Derivative Instruments and Hedging Strategies (Tables)	9 Months Ended
	Sep. 30, 2021
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 were as follows (in thousands): September 30, 2021 December 31, 2020 Derivative Asset Derivative Liability Derivative Asset Derivative Liability Derivatives designated as hedging instruments: Interest rate swap agreements (cash flow hedges) $ — $ 2,476 $ — $ 3,698 — 2,476 — 3,698 Derivatives not designated as hedging instruments: Forward Exchange Contract — — — 893 Conversion option liability on Convertible Senior Notes — 5 — 2 $ — $ 5 $ — $ 895
Schedule of Gains (Losses) on Derivative Instruments not Designated as Hedging Instruments	The Company recognized gains (losses) on derivative instruments not designated as hedging instruments for the nine months ended September 30, 2021 and September 30, 2020 as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Conversion option liability on Convertible Senior Notes $ 3 $ 5 $ (3 ) $ 5,204 Forward currency exchange, option, and future contracts — — 390 — $ 3 $ 5 $ 387 $ 5,204

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
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 September 30, 2021 and December 31, 2020 that are measured at fair value on a recurring basis were as follows (in thousands): September 30, 2021 Level 1 Level 2 Level 3 LIABILITIES Derivative instruments — 2,476 — Conversion Option Liability on Convertible Senior Notes — — 5 December 31, 2020 LIABILITIES Derivative instruments — 4,591 — Conversion Option Liability on Convertible Senior Notes — — 2
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 September 30, 2021 and December 31, 2020 were as follows (in thousands): Estimated Fair Value September 30, 2021 Carrying Amount Level 1 Level 2 Level 3 ASSETS Cash, cash equivalents and restricted cash $ 46,354 $ 46,354 $ — $ — LIABILITIES Long-term debt, including current portion 350,515 — 358,988 — December 31, 2020 ASSETS Cash, cash equivalents and restricted cash $ 36,018 $ 36,018 $ — $ — LIABILITIES Long-term debt, including current portion 472,887 — 470,561 —

Stock Based Compensation (Table

Stock Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Transactions in Connection with Equity Incentive Plans	Transactions in connection with the Company’s Equity Incentive Plans during the nine months ended September 30, 2021 were as follows: Restricted Stock Activity: Outstanding as of December 31, 2020 436,714 Granted (1) 902,214 Vested (202,079 ) Forfeited (5,250 ) Outstanding as of September 30, 2021 1,131,599 Stock Option Activity: Outstanding as of December 31, 2020 1,120,541 Granted 12,500 Exercised — Forfeited (71,684 ) Outstanding as of September 30, 2021 1,061,357 (1) Excludes 157,455 grants of performance-based stock units that are not considered outstanding until such time that they become probable to vest.

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2021
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 (primarily Gulf of Mexico) Africa and Europe (2) Middle East and Asia Latin America Total For the Three Months Ended September 30, 2021 Operating Revenues: Time charter $ 5,289 $ 10,446 $ 13,417 $ 12,630 41,782 Bareboat charter — — — — — Other marine services 1,215 (429 ) 85 1,010 1,881 6,504 10,017 13,502 13,640 43,663 Direct Costs and Expenses: Operating: Personnel 2,428 3,147 5,849 3,627 15,051 Repairs and maintenance 1,266 1,540 1,610 2,120 6,536 Drydocking 239 337 156 39 771 Insurance and loss reserves 462 323 707 697 2,189 Fuel, lubes and supplies 259 1,631 777 1,017 3,684 Other 147 1,424 2,823 823 5,217 4,801 8,402 11,922 8,323 33,448 Direct Vessel Profit $ 1,703 $ 1,615 $ 1,580 $ 5,317 10,215 Other Costs and Expenses: Lease expense $ 621 $ 284 $ 377 $ (173 ) 1,109 Administrative and general 9,134 Depreciation and amortization 3,936 3,296 4,456 2,618 14,306 24,549 Gain on Asset Dispositions, Net 56 Operating Loss $ (14,278 ) United States (primarily Gulf of Mexico) Africa and Europe, Continuing Operations (2) Middle East and Asia Latin America Total For the Nine Months Ended September 30, 2021 Operating Revenues: Time charter $ 10,197 $ 32,385 $ 39,744 $ 35,220 117,546 Bareboat charter 1,163 — — — 1,163 Other marine services 2,488 (922 ) 476 2,223 4,265 13,848 31,463 40,220 37,443 122,974 Direct Costs and Expenses: Operating: Personnel 5,700 10,620 16,435 10,067 42,822 Repairs and maintenance 2,309 4,926 5,319 4,781 17,335 Drydocking 1,891 1,015 2,407 467 5,780 Insurance and loss reserves 1,912 1,108 1,870 1,918 6,808 Fuel, lubes and supplies 703 3,090 2,417 2,569 8,779 Other 448 4,075 4,010 2,313 10,846 12,963 24,834 32,458 22,115 92,370 Direct Vessel Profit $ 885 $ 6,629 $ 7,762 $ 15,328 30,604 Other Costs and Expenses: Lease expense $ 1,988 $ 910 $ 434 $ 89 3,421 Administrative and general 26,897 Depreciation and amortization 11,387 9,908 13,829 8,073 43,197 73,515 Gain on Asset Dispositions, Net 20,436 Operating Loss $ (22,475 ) As of September 30, 2021 Property and Equipment: Historical Cost 248,125 212,491 358,356 170,938 989,910 Accumulated Depreciation (122,437 ) (66,424 ) (85,054 ) (29,263 ) (303,178 ) $ 125,688 $ 146,067 $ 273,302 $ 141,675 $ 686,732 Total Assets (1) $ 149,286 $ 162,815 $ 274,324 $ 211,909 $ 798,334 (1) Total assets by region does not include corporate assets of $103.7 million as of September 30, 2021 . (2) In prior periods Africa and Europe were reported as separate segments. Due to the sale of Windcat Workboats, the Company’s European operations are 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 consolidated with Africa and reported as a consolidated segment and prior period information has been conformed to the new consolidated reporting segment. United States (primarily Gulf of Mexico) Africa and Europe (2) Middle East and Asia Latin America Total For the Three Months Ended September 30, 2020 Operating Revenues: Time charter $ 1,668 $ 10,861 $ 13,672 $ 8,621 $ 34,822 Bareboat charter 731 (55 ) — — 676 Other marine services 473 (255 ) 296 212 726 2,872 10,551 13,968 8,833 36,224 Direct Costs and Expenses: Operating: Personnel 2,481 3,407 5,171 2,342 13,401 Repairs and maintenance 338 1,158 1,564 704 3,764 Drydocking — 481 104 — 585 Insurance and loss reserves 778 398 451 138 1,765 Fuel, lubes and supplies 251 1,091 482 307 2,131 Other 85 773 1,771 444 3,073 3,933 7,308 9,543 3,935 24,719 Direct Vessel (Loss) Profit $ (1,061 ) $ 3,243 $ 4,425 $ 4,898 $ 11,505 Other Costs and Expenses: Lease expense $ 716 $ 429 $ 46 $ 9 $ 1,200 Administrative and general 8,885 Depreciation and amortization 4,961 3,785 4,379 1,708 14,833 24,918 Gain on Asset Dispositions and Impairments 233 Operating Loss, for Continuing Operations $ (13,180 ) United States (primarily Gulf of Mexico) Africa and Europe, Continuing Operations (2) Middle East and Asia Latin America Total For the Nine Months Ended September 30, 2020 Operating Revenues: Time charter $ 7,521 $ 37,927 $ 39,044 $ 16,268 $ 100,760 Bareboat charter 2,178 (55 ) — — 2,123 Other 1,628 (454 ) 1,230 529 2,933 11,327 37,418 40,274 16,797 105,816 Direct Costs and Expenses: Operating: Personnel 7,693 9,887 12,777 4,934 35,291 Repairs and maintenance 1,269 4,206 4,390 1,351 11,216 Drydocking 1,167 745 718 (114 ) 2,516 Insurance and loss reserves 1,267 1,295 1,220 312 4,094 Fuel, lubes and supplies 964 2,407 2,102 574 6,047 Other 257 2,017 3,273 872 6,419 12,617 20,557 24,480 7,929 65,583 Direct Vessel (Loss) Profit, from Continuing Operations $ (1,290 ) $ 16,861 $ 15,794 $ 8,868 $ 40,233 Other Costs and Expenses: Lease expense $ 3,595 $ 1,982 $ 123 $ 27 $ 5,727 Administrative and general 31,519 Depreciation and amortization 15,573 10,700 12,090 3,557 41,920 79,166 Loss on Asset Dispositions and Impairments (15,792 ) Operating Loss, for Continuing Operations $ (54,725 ) As of September 30, 2020 Property and Equipment: Historical Cost 258,710 262,809 365,049 109,802 996,370 Accumulated Depreciation (128,390 ) (65,520 ) (75,013 ) (11,545 ) (280,468 ) $ 130,320 $ 197,289 $ 290,036 $ 98,257 $ 715,902 Total Assets (1) $ 172,218 $ 231,211 $ 312,622 $ 175,164 $ 891,215 (1) Total assets by region does not include corporate assets of $119.2 million, and $46.8 million of discontinued operations as of September 30, 2020. (2) In prior periods Africa and Europe were reported as separate segments. Due to the sale of Windcat Workboats, the Company’s European operations are 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 consolidated with Africa and reported as a consolidated segment and prior period information has been conformed to the new consolidated reporting segment.

Discontinued Operations (Tables

Discontinued Operations (Tables)	9 Months Ended
	Sep. 30, 2021
Discontinued Operations And Disposal Groups [Abstract]
Schedule of Assets Held for Sale	Summarized selected operating result of the Company’s assets related to Windcat Workboats, previously classified as held for sale were as follows (in thousands) Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Windcat Workboats Operating Revenues: Time charter $ — $ 8,764 $ 903 $ 21,923 Other revenue — 709 70 1,579 — 9,473 973 23,502 Costs and Expenses: Operating — 4,409 578 12,078 Direct Vessel Profit — 5,064 395 11,424 General and Administrative Expenses — 1,270 238 3,961 Lease Expense — 190 24 425 Depreciation — 1,780 — 5,007 — 3,240 262 9,393 Operating Income — 1,824 133 2,031 Other Income (Expense) Interest income — 16 2 43 Interest expense — (286 ) (39 ) (828 ) Foreign currency translation loss — 58 89 (951 ) — (212 ) 52 (1,736 ) Operating Loss Before Equity Earnings of 50% or Less Owned Companies, Net of Tax $ — $ 1,612 $ 185 $ 295 Income Tax Expense (Benefit) — 1 — (79 ) Operating Income Before Equity Earnings of 50% or Less Owned Companies $ — $ 1,611 $ 185 $ 374 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax — 155 (16 ) (60 ) Net Income from Discontinued Operations $ — $ 1,766 $ 169 $ 314

Basis of Presentation and Acc_4

Basis of Presentation and Accounting Policies - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Basis Of Presentation And Accounting Policies [Line Items]
Contract with customer, liability	$ 1,170,000	$ 1,987,000		$ 1,170,000	$ 1,987,000	$ 3,307,000	$ 4,755,000
Contract with customer liability current	2,356,000			2,356,000		4,452,000
Construction reserve funds, current	$ 0			0		$ 4,200,000
Capitalized interest costs, including allowance for funds used during construction, total				300,000	700,000
Impairment of long-lived assets owned or leased in vessels				0
Impairment of long-lived assets four owned liftboats					3,900,000
Impairment of long-lived assets two leased-in liftboats					7,400,000
Equity method investment, other than temporary impairment				$ 0	$ 0
Effective income tax rate reconciliation, percent, total				24.56%	34.97%
Class of warrant or right, exercise price of warrants or rights	$ 0.01			$ 0.01
Incremental common shares attributable to conversion of debt securities, total	2,907,500			2,907,500
Prior Periods Adjustment
Basis Of Presentation And Accounting Policies [Line Items]
Incremental common shares attributable to conversion of debt securities, total			2,183,708
Convertible Senior Note
Basis Of Presentation And Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount		2,907,500			2,907,500
Restricted Stock
Basis Of Presentation And Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	1,131,599	469,964		1,120,140	469,964
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements				11,459
Employee Stock Option
Basis Of Presentation And Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	1,061,357	1,120,541		1,061,357	1,120,541
Offshore Support Vessels
Basis Of Presentation And Accounting Policies [Line Items]
Estimated useful life (Year)				20 years
Specialty Vessel
Basis Of Presentation And Accounting Policies [Line Items]
Additional impairment of right-to-use assets					$ 1,200,000
Prepaid Vessel Management Fees
Basis Of Presentation And Accounting Policies [Line Items]
Contract with customer, liability, revenue recognized				$ 2,000,000
Prepaid Charter Modification and Reservation Fees
Basis Of Presentation And Accounting Policies [Line Items]
Contract with customer liability current	$ 300,000			300,000
Demobilization of Offshore Support Vessel
Basis Of Presentation And Accounting Policies [Line Items]
Contract with customer liability current	200,000			200,000
Geographic Distribution, Domestic
Basis Of Presentation And Accounting Policies [Line Items]
Contract with customer, liability	1,200,000			1,200,000
Geographic Distribution, Foreign
Basis Of Presentation And Accounting Policies [Line Items]
Contract with customer, liability	$ 700,000			$ 700,000
Minimum
Basis Of Presentation And Accounting Policies [Line Items]
Equity method investment, ownership percentage	20.00%			20.00%
Minimum | SEACOR Marine Foreign Holdings
Basis Of Presentation And Accounting Policies [Line Items]
Equity method investment, ownership percentage	50.00%			50.00%
Maximum
Basis Of Presentation And Accounting Policies [Line Items]
Equity method investment, ownership percentage	50.00%	50.00%		50.00%	50.00%
Accounting Standards Update 2019-12
Basis Of Presentation And Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true			true
Change in accounting principle, accounting standards update, immaterial effect [true false]	true			true

Basis of Presentation and Acc_5

Basis of Presentation and Accounting Policies - Schedule of Deferred Revenues (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Basis Of Presentation And Accounting Policies [Abstract]
Balance at beginning of period	$ 3,307	$ 4,755
Revenues deferred during the period	490	6
Revenues recognized during the period	(2,627)	(2,774)
Balance at end of period	$ 1,170	$ 1,987

Basis of Presentation and Acc_6

Basis of Presentation and Accounting Policies - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	$ 459,401	$ 451,364	$ 401,836	$ 478,924
Other comprehensive loss	(63)	2,161	4,254	(1,928)
Balance	454,803	436,654	454,803	436,654
Foreign Currency Translation Adjustments Attributable to Parent
Accumulated Other Comprehensive Income Loss [Line Items]
Balance			6,797
Other comprehensive loss			3,818
Balance	10,615		10,615
Derivative Losses on Cash Flow Hedges, net Attributable to Parent
Accumulated Other Comprehensive Income Loss [Line Items]
Balance			(4,007)
Other comprehensive loss			436
Balance	(3,571)		(3,571)
AOCI Attributable to Parent
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	7,107	(2,541)	2,790	1,548
Other comprehensive loss			4,254
Balance	$ 7,044	$ (380)	$ 7,044	$ (380)

Equipment Acquisitions and Di_3

Equipment Acquisitions and Dispositions - Additional Information (Details) $ in Thousands	Jan. 12, 2021USD ($)	Sep. 30, 2021USD ($)Vessel	Sep. 30, 2020USD ($)Vessel
Property Plant And Equipment [Line Items]
Payments to acquire property, plant, and equipment, including fair value hedges		$ 6,600
Number of equipment acquired | Vessel		1
Proceeds from disposition of property and equipment		$ 30,137	$ 20,674
Falcon Global USA Term Loan Facility
Property Plant And Equipment [Line Items]
Setoff of debt under credit facility		22,500
Property plant equipment consideration transferred		$ 30,100
Platform Supply Vessels
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		3	4
Platform Supply Vessels and Fast Support Vessels
Property Plant And Equipment [Line Items]
Proceeds from disposition of property and equipment		$ 25,000
Gain (loss) on disposition of property, plant and equipment		$ 20,900
Anchor Handling Towing Supply
Property Plant And Equipment [Line Items]
Number of equipment sold | Vessel			2
Specialty Vessel Previously Removed from Service
Property Plant And Equipment [Line Items]
Number of equipment sold | Vessel			1
Vessel under Construction and Other Equipment
Property Plant And Equipment [Line Items]
Number of equipment sold | Vessel			1
Equipment
Property Plant And Equipment [Line Items]
Proceeds from disposition of property and equipment			$ 20,700
Property plant equipment consideration transferred			21,600
Gain (loss) on disposition of property, plant and equipment			1,200
Proceeds from deposits			$ 900
Specialty Vessel
Property Plant And Equipment [Line Items]
Number of equipment sold | Vessel			1
Windcat Workboats
Property Plant And Equipment [Line Items]
Proceeds from disposition of property and equipment	$ 38,715
Gain (loss) on disposition of property, plant and equipment	$ 22,756

Equipment Acquisitions and Di_4

Equipment Acquisitions and Dispositions - Schedule of Gain on Sale of Windcat Workboats (Details) - USD ($) $ in Thousands	Jan. 12, 2021	Sep. 30, 2021	Sep. 30, 2020
Property Plant And Equipment [Line Items]
Total Net Proceeds		$ 30,137	$ 20,674
Windcat Workboats
Property Plant And Equipment [Line Items]
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_3

Investments, at Equity, and Advances to 50% or Less Owned Companies - Schedule of Equity Investments (Details) - USD ($) $ in Thousands		Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Schedule Of Investments [Line Items]
Investments at equity		$ 77,426	$ 75,308
Minimum
Schedule Of Investments [Line Items]
Ownership percentage		20.00%
Maximum
Schedule Of Investments [Line Items]
Ownership percentage		50.00%		50.00%
MexMar
Schedule Of Investments [Line Items]
Ownership percentage		49.00%
Investments at equity		$ 57,506	50,037
OSV Partners
Schedule Of Investments [Line Items]
Ownership percentage	[1]	30.40%
Investments at equity	[1]	$ 7,592	9,094
SEACOR Marlin LLC
Schedule Of Investments [Line Items]
Ownership percentage		49.00%
Investments at equity		$ 7,844	7,979
MEXMAR Offshore
Schedule Of Investments [Line Items]
Ownership percentage	[2]	49.00%
Investments at equity	[2]		1,960
Offshore Vessel Holdings
Schedule Of Investments [Line Items]
Ownership percentage		49.00%
Investments at equity		$ 2,203	2,388
Other Offshore Marine Services Joint Ventures
Schedule Of Investments [Line Items]
Investments at equity		$ 2,281	$ 3,850	$ 84,700
Other Offshore Marine Services Joint Ventures | Minimum
Schedule Of Investments [Line Items]
Ownership percentage		20.00%
Other Offshore Marine Services Joint Ventures | Maximum
Schedule Of Investments [Line Items]
Ownership percentage		50.00%		50.00%
[1]	The Company owns 66.7% of the General Partner and 29.7% of the limited partnership interest of OSV Partners.
[2]	This joint venture holds the investment in UP Offshore.

Investments, at Equity, and A_4

Investments, at Equity, and Advances to 50% or Less Owned Companies - Schedule of Equity Investments (Parenthetical) (Details) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020
Maximum
Schedule Of Investments [Line Items]
Equity method investment, ownership percentage		50.00%	50.00%
Minimum
Schedule Of Investments [Line Items]
Equity method investment, ownership percentage		20.00%
OSV Partners
Schedule Of Investments [Line Items]
Equity method investment, ownership percentage	[1]	30.40%
MEXMAR Offshore | Equity Method Investment
Schedule Of Investments [Line Items]
Investment, distribution exceeded		$ 9.4
General Partner
Schedule Of Investments [Line Items]
Equity method investment, ownership percentage		66.70%
Limited Partner | OSV Partners
Schedule Of Investments [Line Items]
Equity method investment, ownership percentage		29.70%
[1]	The Company owns 66.7% of the General Partner and 29.7% of the limited partnership interest of OSV Partners.

Long Term Debt - Schedule of Lo

Long Term Debt - Schedule of Long-term Debt Obligations (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 388,884	$ 521,877
Current portion due within one year	(28,875)	(32,377)
Unamortized debt discount	(35,012)	(44,864)
Deferred financing costs	(3,356)	(4,126)
Long-term debt, less current portion	321,641	440,510
Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	383,384	399,028
Non-Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	5,500	122,849
Convertible Senior Notes | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	125,000	125,000
SEACOR Marine Foreign Holdings Credit Facility | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	89,720	100,750
Sea-Cat Crewzer III Term Loan Facility | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	19,178	21,653
SEACOR Offshore Delta (f/k/a SEACOSCO) Acquisition Debt | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	18,705	19,705
SEACOR Delta (f/k/a SEACOSCO) Shipyard Financing | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	88,649	95,317
SEACOR Alpine Shipyard Financing | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	30,132	31,103
SEACOR 88/888 Term Loan | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	5,500	5,500
SEACOR 88/888 Term Loan | Non-Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	5,500	5,500
Tarahumara Shipyard Financing | Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 6,500
Falcon Global USA Term Loan Facility | Non-Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross		102,349
Falcon Global USA Revolver | Non-Recourse Long-Term Debt
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 15,000

Long Term Debt - Additional Inf

Long Term Debt - Additional Information (Details) $ / shares in Units, $ in Thousands	Jul. 09, 2021USD ($)	Jun. 29, 2021USD ($)	Jun. 24, 2021USD ($)	Jun. 18, 2021USD ($)	Jun. 10, 2021USD ($)Liftboat	Sep. 30, 2021USD ($)$ / shares	Sep. 30, 2020USD ($)
Debt Instrument [Line Items]
Payment to lenders						$ 72,143	$ 16,821
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						$ 2.44
Long-term Debt Obligation
Debt Instrument [Line Items]
Letters of credit outstanding, amount						$ 1,400
Term Loan to Acquire One Vessel
Debt Instrument [Line Items]
Debt instrument, face amount	$ 6,500
Debt instrument, interest rate, effective percentage	6.00%
Debt instrument, maturity year	2025
Conditional Payoff Agreement
Debt Instrument [Line Items]
Payment to lenders			$ 27,500		$ 50,000
Number of liftboats released from mortgages and security arrangements | Liftboat					9
Gain on restructuring of debt			62,000
Reimbursement amount		$ 2,500
Conditional Payoff Agreement | Paid at Signing of Conditional Payoff Agreement
Debt Instrument [Line Items]
Payment to lenders					$ 25,000
Conditional Payoff Agreement | Paid Using Hull and Machinery Insurance Proceeds
Debt Instrument [Line Items]
Payment to lenders				$ 22,500
Conditional Payoff Agreement | Reimbursed from Hull and Machinery Insurance Proceeds
Debt Instrument [Line Items]
Payment to lenders			$ 2,500
Conditional Payoff Agreement | Term and Revolving Loan Facility
Debt Instrument [Line Items]
Principal outstanding under Credit Facility					$ 117,300

Long Term Debt - Schedule of Ga

Long Term Debt - Schedule of Gain on Transactions Under Conditional Payoff Agreement (Details) - USD ($) $ in Thousands	Jun. 24, 2021	Jun. 10, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term Debt, Gross			$ 388,884		$ 521,877
Unamortized debt discount			(35,012)		$ (44,864)
Cash Paid			$ (72,143)	$ (16,821)
Conditional Payoff Agreement
Debt Instrument [Line Items]
Unamortized debt discount	$ (4,600)
Current Liabilities	112,749
Transaction Fees	(755)
Cash Paid	(27,500)	$ (50,000)
Hull and Machinery Insurance Proceeds	(22,500)
Gain on Troubled Debt Restructuring	61,994
Falcon Global USA 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

Leases - Additional Information

Leases - Additional Information (Details)	9 Months Ended
	Sep. 30, 2021Vessel
Anchor Handling Towing Supply Vessels
Lessee Lease Description [Line Items]
Number of operating leases on equipment	2
Fast Support Vessels
Lessee Lease Description [Line Items]
Number of operating leases on equipment	1
Vessels | Minimum
Lessee Lease Description [Line Items]
Operating lease, lease terms (in duration)	2 months
Vessels | Maximum
Lessee Lease Description [Line Items]
Operating lease, lease terms (in duration)	3 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)	303 months

Leases - Summary of Future Mini

Leases - Summary of Future Minimum Payments For Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Operating Leases
Remainder of 2021	$ 1,114
2022	583
2023	527
2024	451
2025	515
Years subsequent to 2025	4,073
Operating lease payments due	7,263
Interest component	(1,994)
Total operating leases	5,269
Current portion of operating lease liabilities	1,269	$ 7,030
Long-term lease liabilities	4,000	4,345
Finance Leases
Remainder of 2021	9
2022	36
2023	36
2024	37
2025	6
Total finance leases	124
Interest component	(8)
Finance Leases	116
Current portion of financing lease liabilities	32	36
Long-term lease liabilities	$ 84	$ 105

Leases - Summary of Components

Leases - Summary of Components of Leases Expense (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Operating lease cost		$ 875	$ 1,030	$ 2,730	$ 5,305
Finance lease cost:
Amortization of finance lease assets	[1]	9	3	19	3
Interest on lease liabilities	[2]	1		2
Short-term lease costs		234	170	691	422
Total Lease expense		$ 1,119	$ 1,203	$ 3,442	$ 5,730
[1]	Included in amortization costs in the consolidated statements of Income (Loss)
[2]	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) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Leases [Abstract]
Operating cash outflows from operating leases	$ (6,365)
Financing cash outflows from finance leases	(21)
Right-of-use assets obtained for operating lease liabilities	$ 955

Leases - Summary of Other Infor

Leases - Summary of Other Information Related to Leases (Details)	Sep. 30, 2021
Leases [Abstract]
Weighted average remaining lease term, in years - operating leases	12 years 7 months 6 days
Weighted average remaining lease term, in years - finance leases	3 years 4 months 24 days
Weighted average discount rate - operating leases	5.70%
Weighted average discount rate - finance leases	4.00%

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory rate	21.00%
Foreign withholding tax	8.89%
Foreign earnings not subject to U.S. Income Tax	(5.47%)
Other	0.14%
Effective income tax rate reconciliation, percent, total	24.56%	34.97%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - Tax Refund Agreement - USD ($) $ in Millions	Jun. 26, 2020	Apr. 30, 2021	Feb. 28, 2021	Mar. 31, 2021
Income Taxes [Line Items]
Expected to cash tax refunds receivable	$ 32.3
Interest received on cash refunds				$ 1.1
Proceeds of cash tax refunds		$ 19.8	$ 12.5

Derivative Instruments and He_3

Derivative Instruments and Hedging Strategies - Schedule of Fair Value of Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Designated as Hedging Instrument | Cash Flow Hedging
Derivative [Line Items]
Derivative Liability	$ 2,476	$ 3,698
Designated as Hedging Instrument | Interest Rate Swap | Cash Flow Hedging
Derivative [Line Items]
Derivative Liability	2,476	3,698
Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Liability	5	895
Conversion option liability on Convertible Senior Notes	$ 5	2
Not Designated as Hedging Instrument | Forward Exchange Contract
Derivative [Line Items]
Derivative Liability		$ 893

Derivative Instruments and He_4

Derivative Instruments and Hedging Strategies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative [Line Items]
Derivative losses on cash flow hedges	$ (54)	$ (82)	$ (22)	$ (2,028)
Maximum
Derivative [Line Items]
Equity method investment, ownership percentage	50.00%	50.00%	50.00%	50.00%
Minimum
Derivative [Line Items]
Equity method investment, ownership percentage	20.00%		20.00%
Minimum | SEACOR Marine Foreign Holdings
Derivative [Line Items]
Equity method investment, ownership percentage	50.00%		50.00%
Cash Flow Hedging
Derivative [Line Items]
Derivative losses on cash flow hedges			$ 1,600	$ (1,100)
Cash Flow Hedging | 3.32% Interest Rate Swap Agreement | Designated as Hedging Instrument | SEACOR Marine Foreign Holdings
Derivative [Line Items]
Derivative, fixed interest rate	3.32%		3.32%
Derivative, notional amount	$ 7,100		$ 7,100
Cash Flow Hedging | 3.195% Interest Rate Swap Agreement | Designated as Hedging Instrument | SEACOR Marine Foreign Holdings
Derivative [Line Items]
Derivative, fixed interest rate	3.195%		3.195%
Derivative, notional amount	$ 38,900		$ 38,900
Cash Flow Hedging | Interest Rate Swap | Designated as Hedging Instrument | SEACOR 88/888
Derivative [Line Items]
Derivative, fixed interest rate	3.175%		3.175%
Derivative, notional amount	$ 5,500		$ 5,500
Cash Flow Hedging | Interest Rate Swap | Designated as Hedging Instrument | MexMar
Derivative [Line Items]
Equity method investment, ownership percentage	49.00%		49.00%
Derivative, notional amount	$ 60,700		$ 60,700
Derivative, number of instruments held, total	5		5
Cash Flow Hedging | Maximum | Interest Rate Swap | Designated as Hedging Instrument | MexMar
Derivative [Line Items]
Derivative, fixed interest rate	2.10%		2.10%
Cash Flow Hedging | Minimum | Interest Rate Swap | Designated as Hedging Instrument | MexMar
Derivative [Line Items]
Derivative, fixed interest rate	1.71%		1.71%
Derivative Liabilities | Fair Value Hedging
Derivative [Line Items]
Recognized gain (loss) on hedged item in fair value hedge			$ 400

Derivative Instruments and He_5

Derivative Instruments and Hedging Strategies - Schedule of Gains (Losses) on Derivative Instruments not Designated as Hedging Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative [Line Items]
Gains (losses) on derivative instruments	$ 3	$ 5	$ 387	$ 5,204
Embedded Derivative Financial Instruments
Derivative [Line Items]
Gains (losses) on derivative instruments	$ 3	$ 5	(3)	$ 5,204
Foreign Exchange Option
Derivative [Line Items]
Gains (losses) on derivative instruments			$ 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	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Liability	$ 2,476	$ 4,591
Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Conversion Option Liability on Convertible Senior Notes	$ 5	$ 2

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Estimated Fair Values of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Reported Value Measurement
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	$ 46,354	$ 36,018
Long-term debt, including current portion	350,515	472,887
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	46,354	36,018
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, including current portion	$ 358,988	$ 470,561

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)PropertyandEquipment	Dec. 31, 2020USD ($)Liftboat
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Impairment charges	$ 0
Number of property and equipment with fair value | PropertyandEquipment	0
Liftboats
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Number of property and equipment with fair value | Liftboat		5
Fair Value, Inputs, Level 2 | Liftboats
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Property and equipment, fair value		$ 43,000,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) R$ in Thousands, $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2021BRL (R$)
Commitments And Contingencies [Line Items]
Remaining capital commitment	$ 0.9
Unrecorded unconditional purchase obligation, due in remainder of fiscal year	9.4
Amount guaranteed under arrangement	0.8
Tax Refund Agreement | SEACOR Holdings
Commitments And Contingencies [Line Items]
Tax refunds remained in account	$ 0.8
Deficiency Notice
Commitments And Contingencies [Line Items]
Cost allocation percentage	70.00%
Deficiency Notice | Seabulk Overseas
Commitments And Contingencies [Line Items]
Cost allocation percentage	30.00%
Minimum | Deficiency Notice
Commitments And Contingencies [Line Items]
Potential range of levies	$ 3.5	R$ 18800
Maximum | Deficiency Notice
Commitments And Contingencies [Line Items]
Potential range of levies	$ 2.4	R$ 12870
FSV Offshore Support Vessels
Commitments And Contingencies [Line Items]
Unrecorded unconditional purchase obligation, maximum quantity	1	1

Stock Based Compensation - Summ

Stock Based Compensation - Summary of Transactions in Connection with Equity Incentive Plans (Details)	9 Months Ended
	Sep. 30, 2021shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding as of the beginning of year (in shares)	1,120,541
Granted (in shares)	12,500
Forfeited (in shares)	(71,684)
Outstanding as of the end of year (in shares)	1,061,357
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding as of the beginning of year (in shares)	436,714
Granted (in shares)	902,214	[1]
Vested (in shares)	(202,079)
Forfeited (in shares)	(5,250)
Outstanding as of the end of year (in shares)	1,131,599
[1]	Excludes 157,455 grants of performance-based stock units that are not considered outstanding until such time that they become probable to vest.

Stock Based Compensation - Su_2

Stock Based Compensation - Summary of Transactions in Connection with Equity Incentive Plans (Parenthetical) (Details)	Sep. 30, 2021shares
Performance Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares outstanding	157,455

Stock Based Compensation - Addi

Stock Based Compensation - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Treasury stock, shares acquired	54,454
Treasury stock, value acquired cost method	$ 272	$ 178

Segment Information - Schedule

Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 30, 2021		Sep. 30, 2020		Sep. 30, 2021		Sep. 30, 2020		Dec. 31, 2020
Segment Reporting Information [Line Items]
Operating Revenues		$ 43,663		$ 36,224		$ 122,974		$ 105,816
Direct Costs and Expenses		33,448		24,719		92,370		65,583
Direct Vessel (Loss) Profit		10,215		11,505		30,604		40,233
Lease expense		1,109		1,200		3,421		5,727
Administrative and general		9,134		8,885		26,897		31,519
Depreciation and amortization		14,306		14,833		43,197		41,920
Other Costs and Expenses		24,549		24,918		73,515		79,166
Gains (Losses) on Asset Dispositions and Impairments, Net		56		233		20,436		(15,792)
Operating Loss, for Continuing Operations		(14,278)		(13,180)		(22,475)		(54,725)
Historical cost		989,910		996,370		989,910		996,370		$ 1,012,873
Accumulated depreciation		(303,178)		(280,468)		(303,178)		(280,468)		(291,538)
Property and equipment		686,732		715,902		686,732		715,902		$ 721,335
Total Assets		798,334	[1]	891,215	[2]	798,334	[1]	891,215	[2]
Time Charter
Segment Reporting Information [Line Items]
Operating Revenues		41,782		34,822		117,546		100,760
Bareboat Charter
Segment Reporting Information [Line Items]
Operating Revenues				676		1,163		2,123
Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues		1,881		726		4,265		2,933
Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses		15,051		13,401		42,822		35,291
Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses		6,536		3,764		17,335		11,216
Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses		771		585		5,780		2,516
Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses		2,189		1,765		6,808		4,094
Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses		3,684		2,131		8,779		6,047
Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses		5,217		3,073		10,846		6,419
UNITED STATES
Segment Reporting Information [Line Items]
Operating Revenues		6,504		2,872		13,848		11,327
Direct Costs and Expenses		4,801		3,933		12,963		12,617
Direct Vessel (Loss) Profit		1,703		(1,061)		885		(1,290)
Lease expense		621		716		1,988		3,595
Depreciation and amortization		3,936		4,961		11,387		15,573
Historical cost		248,125		258,710		248,125		258,710
Accumulated depreciation		(122,437)		(128,390)		(122,437)		(128,390)
Property and equipment		125,688		130,320		125,688		130,320
Total Assets		149,286	[1]	172,218	[2]	149,286	[1]	172,218	[2]
UNITED STATES | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues		5,289		1,668		10,197		7,521
UNITED STATES | Bareboat Charter
Segment Reporting Information [Line Items]
Operating Revenues				731		1,163		2,178
UNITED STATES | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues		1,215		473		2,488		1,628
UNITED STATES | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses		2,428		2,481		5,700		7,693
UNITED STATES | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses		1,266		338		2,309		1,269
UNITED STATES | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses		239				1,891		1,167
UNITED STATES | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses		462		778		1,912		1,267
UNITED STATES | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses		259		251		703		964
UNITED STATES | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses		147		85		448		257
Africa and Europe, Continuing Operations
Segment Reporting Information [Line Items]
Operating Revenues	[3]	10,017		10,551		31,463		37,418
Direct Costs and Expenses	[3]	8,402		7,308		24,834		20,557
Direct Vessel (Loss) Profit	[3]	1,615		3,243		6,629		16,861
Lease expense	[3]	284		429		910		1,982
Depreciation and amortization	[3]	3,296		3,785		9,908		10,700
Historical cost	[3]	212,491		262,809		212,491		262,809
Accumulated depreciation	[3]	(66,424)		(65,520)		(66,424)		(65,520)
Property and equipment	[3]	146,067		197,289		146,067		197,289
Total Assets	[3]	162,815	[1]	231,211	[2]	162,815	[1]	231,211	[2]
Africa and Europe, Continuing Operations | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	[3]	10,446		10,861		32,385		37,927
Africa and Europe, Continuing Operations | Bareboat Charter
Segment Reporting Information [Line Items]
Operating Revenues	[3]			(55)				(55)
Africa and Europe, Continuing Operations | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	[3]	(429)		(255)		(922)		(454)
Africa and Europe, Continuing Operations | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	[3]	3,147		3,407		10,620		9,887
Africa and Europe, Continuing Operations | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	[3]	1,540		1,158		4,926		4,206
Africa and Europe, Continuing Operations | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	[3]	337		481		1,015		745
Africa and Europe, Continuing Operations | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	[3]	323		398		1,108		1,295
Africa and Europe, Continuing Operations | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	[3]	1,631		1,091		3,090		2,407
Africa and Europe, Continuing Operations | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	[3]	1,424		773		4,075		2,017
Middle East and Asia
Segment Reporting Information [Line Items]
Operating Revenues		13,502		13,968		40,220		40,274
Direct Costs and Expenses		11,922		9,543		32,458		24,480
Direct Vessel (Loss) Profit		1,580		4,425		7,762		15,794
Lease expense		377		46		434		123
Depreciation and amortization		4,456		4,379		13,829		12,090
Historical cost		358,356		365,049		358,356		365,049
Accumulated depreciation		(85,054)		(75,013)		(85,054)		(75,013)
Property and equipment		273,302		290,036		273,302		290,036
Total Assets		274,324	[1]	312,622	[2]	274,324	[1]	312,622	[2]
Middle East and Asia | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues		13,417		13,672		39,744		39,044
Middle East and Asia | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues		85		296		476		1,230
Middle East and Asia | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses		5,849		5,171		16,435		12,777
Middle East and Asia | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses		1,610		1,564		5,319		4,390
Middle East and Asia | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses		156		104		2,407		718
Middle East and Asia | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses		707		451		1,870		1,220
Middle East and Asia | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses		777		482		2,417		2,102
Middle East and Asia | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses		2,823		1,771		4,010		3,273
Latin America
Segment Reporting Information [Line Items]
Operating Revenues		13,640		8,833		37,443		16,797
Direct Costs and Expenses		8,323		3,935		22,115		7,929
Direct Vessel (Loss) Profit		5,317		4,898		15,328		8,868
Lease expense		(173)		9		89		27
Depreciation and amortization		2,618		1,708		8,073		3,557
Historical cost		170,938		109,802		170,938		109,802
Accumulated depreciation		(29,263)		(11,545)		(29,263)		(11,545)
Property and equipment		141,675		98,257		141,675		98,257
Total Assets		211,909	[1]	175,164	[2]	211,909	[1]	175,164	[2]
Latin America | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues		12,630		8,621		35,220		16,268
Latin America | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues		1,010		212		2,223		529
Latin America | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses		3,627		2,342		10,067		4,934
Latin America | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses		2,120		704		4,781		1,351
Latin America | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses		39				467		(114)
Latin America | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses		697		138		1,918		312
Latin America | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses		1,017		307		2,569		574
Latin America | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses		$ 823		$ 444		$ 2,313		$ 872
[1]	Total assets by region does not include corporate assets of $103.7 million as of September 30, 2021
[2]	Total assets by region does not include corporate assets of $119.2 million, and $46.8 million of discontinued operations as of September 30, 2020
[3]	In prior periods Africa and Europe were reported as separate segments. Due to the sale of Windcat Workboats, the Company’s European operations are 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 consolidated with Africa and reported as a consolidated segment and prior period information has been conformed to the new consolidated reporting segment.

Segment Information - Schedul_2

Segment Information - Schedule of Segment Reporting Information, by Segment (Parenthetical) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Segment Reporting Information [Line Items]
Assets, Total	$ 902,060	$ 1,017,663
Assets, Discontinued Operations			$ 46,800
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Assets, Total	$ 103,700		$ 119,200

Segment Information - Additiona

Segment Information - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Segment Information [Line Items]
Equity method investments	$ 77,426		$ 75,308
Equity in Gains (Losses) Earnings of 50% or Less Owned Companies	$ 10,600	$ 1,500
Maximum
Segment Information [Line Items]
Equity method investment, ownership percentage	50.00%	50.00%
Minimum
Segment Information [Line Items]
Equity method investment, ownership percentage	20.00%
Other Offshore Marine Services Joint Ventures
Segment Information [Line Items]
Equity method investments	$ 2,281	$ 84,700	$ 3,850
Other Offshore Marine Services Joint Ventures | Maximum
Segment Information [Line Items]
Equity method investment, ownership percentage	50.00%	50.00%
Other Offshore Marine Services Joint Ventures | Minimum
Segment Information [Line Items]
Equity method investment, ownership percentage	20.00%

Discontinued Operations - Addit

Discontinued Operations - Additional Information (Details) - USD ($) $ in Thousands	Jan. 12, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Windcat Workboats Holdings Ltd | Discontinued Operations, Held-for-sale
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net income from operations	$ 200	$ 1,766	$ 169	$ 314

Discontinued Operations - Sched

Discontinued Operations - Schedule of Assets Held for Sale (Details) - Windcat Workboats Holdings Ltd - Discontinued Operations, Held-for-sale - USD ($) $ in Thousands	Jan. 12, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating Revenues:
Operating Revenues		$ 9,473	$ 973	$ 23,502
Costs and Expenses:
Operating		4,409	578	12,078
Direct Vessel Profit		5,064	395	11,424
General and Administrative Expenses		1,270	238	3,961
Lease Expense		190	24	425
Depreciation		1,780		5,007
Total expenses		3,240	262	9,393
Operating Income		1,824	133	2,031
Other Income (Expense)
Interest income		16	2	43
Interest expense		(286)	(39)	(828)
Foreign currency translation loss		58	89	(951)
Other Income (Expense)		(212)	52	(1,736)
Operating Loss Before Equity Earnings of 50% or Less Owned Companies, Net of Tax		1,612	185	295
Income Tax Expense (Benefit)		1		(79)
Operating Income Before Equity Earnings of 50% or Less Owned Companies		1,611	185	374
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax		155	(16)	(60)
Net Income from Discontinued Operations	$ 200	1,766	169	314
Time Charter
Operating Revenues:
Operating Revenues		8,764	903	21,923
Other Revenue
Operating Revenues:
Operating Revenues		$ 709	$ 70	$ 1,579