GLDD Great Lakes Dredge and Dock Corporation

Great Lakes Dredge & Dock Corporation ("Great Lakes" or the “Company”) (NASDAQ: GLDD), the largest provider of dredging services in the United States, announced that it has entered into a $150,000,000 5-year, senior secured second-lien credit agreement (“Second Lien Credit Agreement”) with Guggenheim Credit Funding, LLC, on behalf of one or more clients. The Company borrowed $100,000,000 under the Second Lien Credit Agreement on the Closing Date and has the option to draw an additional $50,000,000 for a period of 12 months following the closing date of the initial loan. The loans under the Second Lien Credit Agreement funded on the Closing Date were used to repay amounts outstanding under the ABL Credit Agreement and to pay fees associated with the transactions and will be used to fund upcoming newbuild payments. The delayed draw portion of the term loans, if funded, will be used to fund future newbuild payments, ongoing working capital and other general corporate purposes.

The Second Lien Credit Agreement contains customary representations and affirmative and negative covenants as well as customary events of default. The obligations under the Second Lien Credit Agreement are secured on a second-priority basis by substantially all of the Company’s assets. Further details on the terms of the Second Lien Credit Agreement can be found in the Company’s Form 8-K for the Second Lien Credit Agreement which will be filed within the next four business days.

Scott Kornblau, Great Lakes’ Senior Vice President, Chief Financial Officer, and Treasurer commented, “The second-lien financing shores up our balance sheet and provides additional liquidity to complete our new build program. The delayed draw feature allows Great Lakes to lock in a commitment for additional long-term capital while giving us the flexibility to pursue financing alternatives, including Title XI. We are confident in our long-term strategy and remain committed to delivering value to our shareholders and maintaining a strong balance sheet.”

Lazard Frères & Co. LLC acted as placement agent and sole financial advisor to the Company in connection with the Second Lien Credit Agreement.

The Company Great Lakes Dredge & Dock Corporation is the largest provider of dredging services in the United States. In addition, Great Lakes is fully engaged in expanding its core business into the rapidly developing offshore wind energy industry. The Company has a long history of performing significant international projects. The Company employs experienced civil, ocean and mechanical engineering staff in its estimating, production and project management functions. In its over 134-year history, the Company has never failed to complete a marine project. Great Lakes owns and operates the largest and most diverse fleet in the U.S. dredging industry, comprised of approximately 200 specialized vessels. Great Lakes has a disciplined training program for engineers that ensures experienced-based performance as they advance through Company operations. The Company’s Incident-and Injury-Free® (IIF®) safety management program is integrated into all aspects of the Company’s culture. The Company’s commitment to the IIF® culture promotes a work environment where employee safety is paramount.

Cautionary Note Regarding Forward-Looking Statements Certain statements in this press release may constitute "forward-looking" statements as defined in Section 21E of the Securities Exchange Act of 1934 (the "Exchange Act"), the Private Securities Litigation Reform Act of 1995 (the "PSLRA") or in releases made by the Securities and Exchange Commission (the "SEC"), all as may be amended from time to time. Such forward-looking statements involve known and unknown risks, uncertainties and other important factors that could cause the actual results, performance or achievements of Great Lakes and its subsidiaries, or industry results, to differ materially from any future results, performance or achievements expressed or implied by such forward-looking statements. Statements that are not historical fact are forward-looking statements. These cautionary statements are being made pursuant to the Exchange Act and the PSLRA with the intention of obtaining the benefits of the "safe harbor" provisions of such laws. Great Lakes cautions investors that any forward-looking statements made by Great Lakes are not guarantees or indicative of future events.

Although Great Lakes believes that its plans, intentions and expectations reflected in this press release are reasonable, actual events could differ materially. The forward-looking statements contained in this press release are made only as of the date hereof and Great Lakes does not have or undertake any obligation to update or revise any forward-looking statements whether as a result of new information, subsequent events or otherwise, unless otherwise required by law.

For further information contact: Tina BaginskisDirector, Investor Relations630-574-3024