Proxy Results, Management Change/Compensation (Form 8-K)

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

Great Lakes Dredge & Dock Corporation (the "Company") held its 2025 Annual Meeting of Stockholders on May 8, 2025 (the "Annual Meeting"). At the Annual Meeting, the Company's stockholders approved an amendment to the Company's 2021 Long-Term Incentive Plan (the "2021 Plan"), which had been previously approved by the Board of Directors of the Company, subject to stockholder approval. The amendment increases the total number of shares available for issuance under the 2021 Plan by 3,000,000 shares.

The 2021 Plan was described in Proposal 4 of the Company's definitive proxy statement filed with the Securities and Exchange Commission on March 26, 2025 in connection with the Annual Meeting. The descriptions of the 2021 Plan contained herein and therein are qualified in their entirety by the full text of the 2021 Plan, as amended, which is filed as Exhibit 10.1 to this Current Report on Form 8-K and is incorporated herein by reference.

Item 5.07 Submission of Matters to a Vote of Security Holders.

In connection with the Annual Meeting, proxies were solicited pursuant to Section 14(a) of the Securities Exchange Act of 1934. Matters voted upon were (1) the election of two directors, each to serve for a one-year term expiring at the 2026 Annual Meeting of Stockholders and to hold office until his respective successor is elected and qualified or until his earlier death, disqualification, resignation or removal; (2) the ratification of the appointment by the Audit Committee of the Board of Directors of Deloitte & Touche, LLP as the Company's independent registered public accounting firm for the year ending December 31, 2025; (3) approval, on a non-binding advisory basis, of the Company's executive compensation; (4) the approval of the First Amendment to the Great Lakes Dredge & Dock Corporation 2021 Long-Term Incentive Plan; and (5) the approval of the Great Lakes Dredge & Dock Corporation 2025 Employee Stock Purchase Plan. A total of 59,851,413 votes were cast. The results with respect to each matter are set out below:

1) The stockholders elected each of the two director nominees to serve for a one-year term expiring at the Company's 2026 Annual Meeting of Stockholders. The result of the vote taken at the Annual Meeting was as follows:

2) The stockholders ratified the appointment of Deloitte & Touche LLP as the Company's independent registered accounting firm for the fiscal year ending December 31, 2025 with the following vote:

3) The stockholders adopted a resolution approving, on an advisory basis, the compensation paid to the Company's named executive officers. The result of the vote taken at the Annual Meeting was as follows:

4) The stockholders approved the First Amendment to the Great Lakes Dredge & Dock Corporation's 2021 Long-Term Incentive Plan. The result of the vote taken at the Annual Meeting was as follows:

5) The stockholders approved the Great Lakes Dredge & Dock Corporation 2025 Employee Stock Purchase Plan. The result of the vote taken at the Annual Meeting was as follows: