Kathleen M. Shanahan - 30 Sep 2025 Form 4 Insider Report for Great Lakes Dredge & Dock CORP (GLDD)

Role: Director
Signature: /s/Vivienne R. Schiffer, by Power of Attorney
Issuer symbol: GLDD
Transactions as of: 30 Sep 2025
Net transactions value: $0
Form type: 4
Filing time: 01 Oct 2025, 17:02:21 UTC
Previous filing: 01 Jul 2025
Next filing: 12 Nov 2025
SEC: View on sec.gov

Reporting Owners (1)

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	01 Oct 2025	0001292085

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
holding	GLDD	Common Stock						70,524	30 Sep 2025	Direct

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

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	+2,106	+20%	$0.000000	12,777	30 Sep 2025	Common Stock	2,106		Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Deferred Stock Units ("DSUs") granted September 30, 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.