Great Lakes Dredge & Dock 8K Regulation FD Disclosure | GLDD 16 Sep 15

INVESTOR

PRESENTATION

GREAT LAKES DREDGE & DOCK CORPORATION > INFRASTRUCTURE SOLUTIONS

2015 | Q2

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Exhibit 99.1

SAFE HARBOR

GREAT LAKES DREDGE & DOCK CORPORATION > INFRASTRUCTURE SOLUTIONS

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This presentation includes “forward-looking” statements within the meaning of Section 27A of the

Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934, the Private Securities

Litigation Reform Act of 1995 or in releases made by the SEC, all as may be amended from time to time.

Such statements include declarations regarding the intent, belief, or current expectation of the Company

and its management. The Company cautions that any such forward-looking statements are not

guarantees of future performance, and involve a number of risks, assumptions and uncertainties that

could cause actual results of the Company and its subsidiaries, or industry results, to differ materially

from those expressed or implied by any forward-looking statements contained herein, including, but not

limited to, as a result of the factors, risks and uncertainties described in other securities filings of the

Company made with the SEC, such as the Company’s most recent Report on Form 10-K. You should

not place undue reliance upon these forward-looking statements. Forward-looking statements provided

herein are made only as of the date hereof or as a specified date herein and the Company does not

have or undertake any obligation to update or revise them, unless required by law.

PRESENTERS

GREAT LAKES DREDGE & DOCK CORPORATION > INFRASTRUCTURE SOLUTIONS

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Chief Executive Officer,

Director

> JONATHAN BERGER

Board member since December

2006

Former Managing Director and

Co-head of Corporate Finance

for Navigant Consulting, Inc.

Former partner at KPMG, LLP and

past National Partner in charge of

Corporate Finance at KPMG

Senior Vice President

& Chief Financial Officer

> MARK MARINKO

Elected Senior Vice President & Chief

Financial Officer in June 2014

Most recently served as President of

the Consumer Services Division at

TransUnion, after serving as Controller

and Vice President of Finance at

TransUnion

since 1996

Has over 30 years of financial

leadership practice, specializing in

accounting, finance, sales, systems

and business operations

Investor Relations

> MARY MORRISSEY

Joined Great Lakes’ Corporate

Development team in August

2012

Assumed Investor Relations

position June 2014

Has a management consulting

and commercial banking

background

ABOUT US

GREAT LAKES DREDGE & DOCK CORPORATION > INFRASTRUCTURE SOLUTIONS

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GREAT LAKES DREDGE & DOCK CORPORATION > INFRASTRUCTURE SOLUTIONS

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> WHO IS GREAT LAKES

DREDGE & DOCK CORPORATION?

ABOUT US

TTM Revenue

$861 million

TTM EBITDA*

$83 million

Company Backlog at 6/30/2015

$752 million

Incident-

and Injury-Free (IIF) Company

*Adjusted EBITDA from continuing operations

Domestic Dredging

International Dredging

Environmental & Remediation Services

Geotechnical Services

Marine & Environmental

Infrastructure Contractor

GREAT LAKES DREDGE & DOCK CORPORATION > INFRASTRUCTURE SOLUTIONS

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PROTECTED DOMESTIC DREGING MARKET &

PROVEN RECORD

“Dredging Act” and “Jones Act” effectively serve as

barriers to entry for non-U.S.-owned

dredging companies

Only U.S. dredging operator with significant international

presence

Portfolio of flexible fleet enables repositioning of vessels

as necessary

Demonstrated record of successful project completion

having never failed to complete a marine project over

125-year history

Added sediment & soil remediation capabilities with

2012 Terra Contracting acquisition

Magnus acquisition in 2014 added geotechnical

capabilities and diversifies geographic footprint across

the U.S.

Rivers & lakes’ inland dredging fleet enables Company

to pursue work that has a water-based component to it

ENVIRONMENTAL & GEOTECHNICAL

CAPABILITIES

ABOUT US

6/30/2015 YTD TOTAL CONSOLIDATED COMPANY

REVENUE –

$359 MILLION

2014 TOTAL CONSOLIDATED COMPANY REVENUE

–

$806 MILLION

89%

11%

Dredging

Environmental & Remediation

86%

14%

Dredging

Environmental & Remediation

GREAT LAKES DREDGE & DOCK CORPORATION > INFRASTRUCTURE SOLUTIONS

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38%

26%

11%

28%

22%

18%

ABOUT US

> LARGEST PROVIDER OF DREDGING

2013 DREDGING

REVENUE

BY WORK TYPE

$643 MILLION

2014 DREDGING

REVENUE

BY WORK TYPE

$698 MILLION

2013 DOMESTIC

DREDGING BID

MARKET SHARE

DOM. BID MARKET:

$1,276 MILLION

2014 DOMESTIC

DREDGING BID

MARKET SHARE

DOM. BID MAKET:

$1,520 MILLION

24%

36%

22%

14%

CAPITAL

COASTAL PROTECTION

RIVERS & LAKES

FOREIGN

MAINTENANCE

54%

22%

10%

GREAT LAKES

WEEKS

MANSON

OTHER

ORION

DUTRA

NORFOLK

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ABOUT US

CAPITAL

COASTAL PROTECTION

MAINTENANCE

INTERNATIONAL

RIVERS & LAKES

Deepening ports, coastal restoration,

land reclamation, and excavation of

underwater trenches

Bid Market Share* 46%

Creating and rebuilding beaches

Bid Market Share* 58%

Maintaining depth of shipping channels

Bid Market Share* 33%

International land reclamations, channel

deepening and port infrastructure development

3-year Average Revenue $135M

Inland maintenance and lake dredging,

Environmental and habitat restoration

Bid Market Share* 50%

*The Company’s

dredging bid market is defined as the aggregate dollar value of domestic projects on which the Company bid or could have

bid if not for capacity constraints. Bid market share represents bid market average over the prior three years.

GREAT LAKES DREDGE & DOCK CORPORATION > INFRASTRUCTURE SOLUTIONS

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19 Vessels*: 16 U.S., 4 Middle East

(All U.S. flagged)

Including the only two large electric

cutterhead

dredges available in the

U.S. for environmentally sensitive

regions requiring lower emissions

Vessels: 4 U.S., 3 Middle East,

(4 U.S. flagged)

Highly mobile, able to operate

in rough waters

Little interference with other

ship traffic

5 Vessels: 4 U.S., 1 International,

(All U.S. flagged)

Operates one of two environmentally

friendly electric clamshell dredges in

the U.S.

Maneuverability in tight areas such

as docks and terminals

HYDRAULIC

HOPPER

MECHANICAL

ABOUT US

*Note: Nine vessels are hydraulic but have less capacity, ideal for rivers and environmental dredging.

+ Over 140 Material Transportation Barge and Other Specialized Support Vessels

> LARGE & FLEXIBLE FLEET FOR DREDGING, U.S. & INTERNATIONAL

MARKETS

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ABOUT US

$140 million Suez

Canal deepening

project

$77 million Shell

Island West project

$200+ million

Hurricane Sandy-

related New

Jersey shore

protection projects

> DREDGING WORLDWIDE

WHERE WE HAVE WORKED

COUNTRIES

WHERE WE SEE

OPPORTUNITIES

CURRENT PROJECTS / RECENT AWARDS

$135 million

Savannah Harbor

deepening project

$206 million

PortMiami

deepening project

GREAT LAKES DREDGE & DOCK CORPORATION > INFRASTRUCTURE SOLUTIONS

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ABOUT US

> WIDE RANGE OF ENVIRONMENTAL & GEOTECHNICAL SERVICES

EXPECTED TO DIVERSIFY BEYOND CORE DREDGING

SITE

PREPARATION &

DEVELOPMENT

TBD

Excavation and management of

contaminated soils

Stabilize sludge ponds and construct and

close waste repositories

Mine reclamation

Wetlands construction

Hazardous waste remediation and removal

Landfill closure and capping

Slurry cutoff walls

Custom designed slurry backfills

Deep soil-mixed cutoff walls

Permeable reactive barriers

Biopolymer collection trenches

Soil stabilization & ground improvement

ENVIRONMENTAL REMEDIATION

GEOTECHNICAL SERVICES

SEDIMENTS & WETLANDS

Design and construction of man-made

wetlands

Contouring/shaping

Contaminated sediment excavation

Stream channel construction and

restoration

Hazardous waste remediation

Water management

Site restoration

GREAT LAKES DREDGE & DOCK CORPORATION > INFRASTRUCTURE SOLUTIONS

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$6.4

$6.3

$5.4

$3.6

$3.1

$2.7

Conservation & Development

Construction

Site Remediation

Building Remediation

Emergency Response

Special / Haz. Waste

Other Rem. & Env. Clean-Up

ABOUT US

$27.5 BILLION*

Highly fragmented –

~5,000 small, local and regional

service providers with few large, public companies

Lower level of capital intensity compared to dredging

Drivers include:

Aging U.S. infrastructure –

estimated $3.6 trillion

investment needed for U.S. infrastructure by 2020

Expansion and improvement of midstream assets

and refining capacity: over $250 billion estimated

spend in the next 25 years in natural gas, natural

gas liquids and oil transmission infrastructure

Government oversight of environmental practices

with tightened mandates and increased legislation

Superfund sites in the Northeast are now

obtaining funding for environmental clean-up and

remediation to develop brownfields

Natural disasters

2014 ENV. REMEDIATION

& GEOTECHNICAL SERVICES –

$27.5B

> MARKET FOR ENVIRONMENTAL REMEDIATION EXPECTED TO GROW,

PRIMARILY DRIVEN BY THE PRIVATE SECTOR

MARKET OVERVIEW & DRIVERS

Great Lakes was ranked #45

on Engineering News-Record’s

“2014 Top 200 Environmental Firms List,”

the Company’s inaugural year on the list

Source: IBISworld, American Society of Civil Engineering and GLDD internal estimates

FUTURE GROWTH

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DIVERSIFY

CAPITALIZE

OPTIMIZE

ENHANCE

BUILD

Build upon Great

Lakes’ preeminent

position in the U.S.

dredging market

Enhance the

Company’s

operating capabilities

via prudent and

cost-effective

investments and

asset management

Optimize the

Company’s

presence in foreign

markets

Capitalize on

adjacent market

opportunities in the

Company’s

domestic markets

Pursue growth

through diversification

in the environmental

& remediation

segment

FUTURE GROWTH

> GREAT LAKES INTENDS TO GROW THE BUSINESS BY CONTINUING

TO EXECUTE THE FOLLOWING STRATEGIES:

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FUTURE GROWTH

> BUILD UPON GREAT LAKES’ PREEMINENT POSITION IN THE U.S.

DREDGING MARKET

43%

26%

10%

Great Lakes

Weeks

Manson

Dutra

Norfolk

Orion

Cashman

Other

3 YR. AVG. DOMESTIC DREDGING BID MARKET SHARE

(DOMESTIC BID MARKET: $3,736 MILLION)

Great Lakes is

the largest provider of

dredging services

in the United States

ATTRACTIVE NEAR & LONG-TERM CATALYSTS IN U.S. DREDGING MARKET

Deepening of U.S. Ports Post-Panama Canal Deepening

Growing use of “post-Panamax” vessels is expected, requiring the deepening of

many ports along the East Coast in order to accommodate the vessels

Sandy Supplemental Appropriations Bill

Provides an additional $800 million for dredging beyond the Corps’ annual budget;

increased attention on coastal restoration anticipated to result in increased

sustainable funding in future years

Provides a very high level of attention and funding for coastal protection work that

is anticipated to result in increased sustainable funding in future years

Gulf Coast Restoration

RESTORE Act requires 80% of penalties associated with Deepwater Horizon oil

spill to be deposited into a coastal restoration works fund, a portion of which will

be allocated to dredging

BP agreed to $18B settlement in July 2015

Water Resources Reform & Development Act (WRRDA) & Harbor

Maintenance Trust Fund (HMTF)

First water legislation to be signed into law since 2007; authorizes dozens of

large-scale water infrastructure projects

Calls for HMTF monies (~$1.5 billion / year) to be fully allocated to harbor

maintenance by 2025

Sources: Congressional Research Service, RESTORE Act, WRRDA

GREAT LAKES DREDGE & DOCK CORPORATION > INFRASTRUCTURE SOLUTIONS

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DELAWARE 40’

NEW YORK 50’

BOSTON 40’

CHARLESTON 45’

SAVANNAH 42’

JACKSONVILLE 40’

PORT EVERGLADES 42’

MIAMI 42’

MOBILE 45’

NEW ORLEANS 45’

HOUSTON 45’

SAN DIEGO 35’

PORTS WITH DEEPENING EXPEDITED

BY OBAMA ADMINISTRATION

PORTS WITH PLANS FOR EXPANSION

> PORTS WITH PLANS FOR EXPANSION*

International trade, particularly in the intermodal container shipping business, is undergoing significant change as a

result of the Panama Canal expansion. Many shipping lines have announced plans to deploy larger ships which, due to

channel dimension requirements, currently cannot use many U.S. East and Gulf Coast ports.

FUTURE GROWTH

*GLDD

recently

completed

the

PortMiami

deepening

project,

deepening

portion

the

Port

NY/

and

recently

began

the

first

phase

the

Savannah

deepening

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FUTURE GROWTH

Investment Overview

Total estimated investment of $140M

Invested to date as of 6/30/2015 of $68M

Financial Benefits

Provides access to an unencumbered asset on our

balance sheet to finance a potential future addition to

the dredging fleet

Five year accelerated depreciation for tax purposes is

expected to create a tax shield

Expected potential annual EBITDA of $20M –

$30M

Timeline

Executed contract with shipyard January 2014

Construction began September 2015

Expected completion is 4Q 2016

> ENHANCE OPERATING CAPABILITIES VIA PRUDENT AND COST-

EFFECTIVE INVESTMENTS & ASSET MANAGEMENT

Building the new hopper dredge represents a strategic investment by

the Company in providing the most productive, efficient and capable

dredging equipment in the

domestic industry.

Performance Advantages

15,000 cubic yards capacity is significantly higher than a

traditional self-propelled hopper dredge enabling the ATB

to be the low cost producer

Required crew complement is significantly reduced

Construction cost is less than a traditional self-propelled

hopper dredge

Reduced insurance premiums

Improved fuel efficiency

Improved operating margins

BUILDING ARTICULATED TUG & BARGE (ATB) HOPPER DREDGE

GREAT LAKES DREDGE & DOCK CORPORATION > INFRASTRUCTURE SOLUTIONS

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FUTURE GROWTH

> HISTORICALLY, DOMESTIC HOPPER MARKET HAS BEEN STRONG,

AND THERE ARE ATTRACTIVE FUTURE OPPORTUNITIES

ATB Build Progress –

Barge “Ellis

Island”

Historical hopper markets

The ATB will be effective in all major hopper

markets, including coastal protection, capital and

maintenance projects

It will be capable of competing in non-traditional

hopper markets: mechanical and hydraulic

maintenance projects, as well as hydraulic coastal

projection projects

New opportunities for ATB

Gulf Coast restoration –

funded primarily by the BP

settlement

HMTF –

incremental maintenance dredging each year

until 2025

Superstorm

Sandy coastal protection projects

South Florida beaches –

offshore borrow areas near

depletion; sand source >100NM away being considered

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FUTURE GROWTH

> OPTIMIZE PRESENCE IN ATTRACTIVE FOREIGN MARKETS

Great Lakes is the only U.S. dredging contractor with significant international presence

Three-year average annual revenue of $135M

Work includes land reclamations, channel deepening and port infrastructure

development

Over the last ten years, GLDD has performed dredging work in the Middle

East, Africa, India, Australia, the Caribbean and Central and South America

Recently completed $140M contract to deepen and widen a portion of the

Suez Canal in October 2014

OVERVIEW

Great Lakes’ international

strategy is to work in the

most attractive markets that

enable consistent utilization

and optimization of

the international fleet

Oresund Fixed Link

Durrat

Al Bahrain

Saipem

Do Brasil

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FUTURE GROWTH

> CAPITALIZE ON ADJACENT MARKET OPPORTUNITIES IN THE

COMPANY’S DOMESTIC MARKETS

$89M contract awarded

2/2014

Rivers & lakes division is

dredging nearly 11 million

cubic yards of material

from Basins 1-4 of Lake

Decatur

Environmental &

remediation segment is

responsible for

rehabilitation of Oakley

Sediment Basin

Estimated completion in

2019

Strategy includes pursuing environmental projects with a water component

ACTIVE PROJECT

EXAMPLES OF FUTURE POTENTIAL OPPORTUNITIES

EPA approved clean-up plan for

Gowanus Canal Superfund site in

September 2013

Clean-up is expected to cost ~$500M

and will be spread among more than

three dozen entities

Should be completed by 2022

Plan entails removing contaminated

sediment from the bottom of canal by

dredging, capping the dredged areas

and implementing controls on

combined sewer overflows to prevent

future contamination

Decatur Lake Project

Passaic River Superfund

EPA finalizing a plan for the Passaic

River Superfund –

options range from

removing 1M cubic yards (CY) of

toxic sediment from the river bottom

to just under 10M CY

Cost is expected to range from

$500M to $1.7B

Several companies are responsible

for the cleanup; one responsible

party, Occidental Chemical, reached

a $190M settlement with EPA in

September 2014

Gowanus Canal Superfund Site

Sources: EPA, Bloomberg

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FUTURE GROWTH

> Leverage our core competencies and strengths to capture market share

in the environmental services market

Strong reputation

Accurate estimating

Project mobilization and execution

Creativity

Engineering innovation

Commitment to safety

Stringent controls

Capitalize on GLDD’s scale and

expanded capabilities to bid on

larger, more complex projects

Establish new customers and

focus on deepening existing

relationships with customers in

high potential end markets, e.g.

Oil and Gas, Mining and Utilities

Target end-users directly to

capture more value

Expand footprint geographically to

smooth out seasonality

STRATEGY

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PURSUE ATTRACTIVE END MARKETS TO GROW ENVIRONMENTAL

BUSINESS

Sources: EPA, American Society of Civil Engineering, USACE National Levee Database and Earthworks, IHS Economic Consulting

FUTURE GROWTH

Utilities

Coal combustion residuals

(CCRs), commonly known as

coal ash, are one of the

largest industrial waste

streams generated in the

U.S.

CCR disposal occurs at more

than 310 active on-site

landfills and at more than 735

active on-site surface

impoundments

EPA Final Rule regulating

CCRs goes into effect

October 2015

Levee & Dam Maintenance

Most common type of flood

defense and mitigation

Approximately 100,000 miles

of levees exist in the U.S.

Average age is 54 years

500,000+ abandoned and

inactive hardrock

mines in the

U.S.

$50B estimated clean-up

HR 963, the Hardrock

Mining

Reform and Reclamation Act of

2015, currently in

subcommittee, would charge

the mining industry a

reclamation fee that would

generate $200 million per year

to fund abandoned mine

restoration

Mine Reclamation

Oil & Gas

Driven by the shale and natural

gas growth in the United States,

significant investment has been

made in midstream and

downstream oil and gas

infrastructure

Between 2014 and 2020, $80

billion is projected to be

invested annually in U.S.

midstream and downstream

petroleum infrastructure

INVESTMENT

HIGHLIGHTS

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INVESTMENT HIGHLIGHTS

> BACKLOG

BY WORK TYPE | $ IN MILLIONS

*Includes low bids and options pending award as of 6/31/2015.

$420.3

$543.4

$669.5

$752.0

$795.6

10%

32%

20%

34%

32%

19%

26%

32%

24%

28%

14%

11%

52%

18%

20%

13%

11%

20%

19%

$100

$200

$300

$400

$500

$600

$700

$800

$900

12/31/2012

12/31/2013

12/31/2014

6/30/2015

06/30/2015*

CAPITAL

COASTAL PROTECTION

RIVERS & LAKES

FOREIGN

MAINTENANCE

ENVIRONMENTAL & REMEDIATION

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$100

$200

$300

$400

$500

$600

$700

$800

$900

2011

2012

2013

2014

YTD

6/30/2014

YTD

6/30/2015

CAPITAL

MAINTENANCE

COASTAL PROTECTION

FOREIGN

RIVERS & LAKES

ENVIRONMENTAL & REMEDIATION

17.3%

12.7%

13.5%

9.6%

8.9%

9.1%

10%

12%

14%

16%

18%

20%

$20

$40

$60

$80

$100

$120

2011

2012

2013

2014

YTD

6/30/2014

YTD

6/30/2015

$90.1

> ANNUAL REVENUE

> ANNUAL ADJUSTED EBITDA*

$588.4

*Adjusted EBITDA from continuing operations represents net income (loss), adjusted for net interest expense, income taxes, depreciation

and amortization expense, accelerated maintenance expense, goodwill impairment, debt restructuring expense and gains on bargain

purchase acquisitions.

INVESTMENT HIGHLIGHTS

$731.4

$806.8

$359.1

$413.4

$74.7

$98.1

$77.1

$31.8

$37.7

$520.1

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> CAPEX

$ IN MILLIONS

> LEVERAGE

$0.0

$20.0

$40.0

$60.0

$80.0

$100.0

$120.0

2011

2012

2013

2014

YTD

6/30/2015

GROWTH

MAINTENANCE

$30.6

(D)

$76.3 (A)

$62.1 (B)

$103.7 (C)

2011

2012

2013

2014

6/30/2015

NET DEBT / EBITDA

3.5x

4.4x

(A)

Includes $13.7 related to the Empire Pipeline, $3.6 related to the ATB Hopper Dredge, $6.8 related to two new scows and $11.7

related to the Terra Contracting

acquisition.

(B)

Includes $17.1 related to the ATB Hopper Dredge.

(C)

Includes $33.8 related to the ATB Hopper Dredge, $4.0 million related to the Team acquisition for which GLDD recognized a $2.2 million gain on bargain

purchase and $11.6 million related to the Magnus acquisition.

(D)

Includes $12.1 million related to the ATB Hopper Dredge and excludes $16.0 million for the purchase of the Terrapin Island dredge that was previously on an

operating lease.

INVESTMENT HIGHLIGHTS

3.7x

$22.9

1.6x

APPENDIX

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APPENDIX

> RECONCILIATION OF NET INCOME (LOSS) TO ADJUSTED EBITDA

FISCAL YEAR ENDING DECEMBER 31,

SIX MONTHS

ENDED JUNE 30,

($ IN MILLIONS)

2011

2012

2013

2014

2015

NET INCOME (LOSS)

$16.5

$(2.7)

$(34.4)

$10.3

$(6.6)

$(5.7)

INCOME (LOSS) FROM DISCONTINUED

OPERATIONS, NET OF INCOME TAXES

0.9

(9.6)

(54.9)

$(10.4)

(8.1)

NET INCOME (LOSS) ATTRIBUTABLE TO

NONCONTROLLING INTEREST

(0.7)

0.6

INCOME (LOSS) FROM CONTINUING OPERATIONS

$16.3

$6.3

$19.9

$20.7

1.4

(5.7)

ADJUSTED FOR:

ACCELERATED MAINTENANCE EXPENSES

4.7

LOSS ON EXTINGUISHMENT OF DEBT

5.1

INTEREST EXPENSE –

NET

21.4

20.9

21.9

20.0

10.0

11.2

INCOME TAX PROVISION (BENEFIT)

9.9

5.4

10.5

(11.5)

0.6

(3.6)

DEPRECIATION AND AMORTIZATION

37.3

37.4

46.6

50.1

21.9

33.0

IMPAIRMENT OF GOODWILL

2.8

GAIN ON BARGAIN PURCHASE ACQUISITION

(2.2)

ADJUSTED EBITDA FROM CONTINUING OPERATIONS

$90.1

$74.7

$98.9

$77.1

$31.8

$37.7

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APPENDIX

> STOCK PERFORMANCE

INITIAL INVESTMENT $100

Note: Great Lakes went public in December 2006

12.31.06

12.31.07

12.31.08

12.31.09

12.31.10

12.31.11

12.31.12

12.31.13

12.31.14

6.30.15

GLDD

100.0%

135.2%

64.3%

100.5%

114.3%

86.2%

138.4%

142.6%

132.7%

92.4%

PEERS

100.0%

132.6%

89.3%

96.6%

96.8%

79.3%

96.3%

141.7%

123.3%

124.9%

RUSSELL

100.0%

97.3%

63.4%

79.4%

99.5%

94.1%

107.8%

147.7%

152.9%

159.2%

NASDAQ

100.0%

109.8%

65.3%

93.9%

109.8%

107.9%

125.0%

172.9%

196.1%

206.5%

50%

70%

90%

110%

130%

150%

170%

190%

210%

230%

12/31/2006

12/31/2007

12/31/2008

12/31/2009

12/31/2010

12/31/2011

12/31/2012

12/31/2013

12/31/2014

6/30/2015

GLDD

Peers

Russell 2K

NASDAQ

Great Lakes Dredge & Dock (GLDD) 8-KRegulation FD Disclosure