| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| Shanahan Kathleen M | Director | C/O GREAT LAKES DREDGE & DOCK CORP., 9811 KATY FREEWAY, SUITE 1200, HOUSTON | /s/Vivienne R. Schiffer, by Power of Attorney | 05 Jan 2026 | 0001292085 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| holding | GLDD | Common Stock | 70,524 | 31 Dec 2025 | Direct |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Underlying Class | Amount | Exercise Price | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | GLDD | Deferred Stock Units | Award | $0 | +1,925 | +15% | $0.000000 | 14,702 | 31 Dec 2025 | Common Stock | 1,925 | Direct | F1 |
| Id | Content |
|---|---|
| F1 | Deferred Stock Units ("DSUs") granted December 31, 2025 and deferred pursuant to the Company's Director Deferral Plan. The DSUs will be payable in common stock on a 1-for-1 basis in three equal annual installments beginning January 15, 2026. |