Great Lakes Dredge (GLDD) director converts DSUs into common stock

Rhea-AI Filing Summary

Great Lakes Dredge & Dock Corp. director Kathleen M. Shanahan reported stock unit conversions into common shares. On January 15, 2026, she exercised 2,849 Deferred Stock Units (DSUs) and separately 3,002 DSUs at an exercise price of $0 per share, receiving the same number of Great Lakes Dredge & Dock common shares for each transaction.

Each DSU represents the right to receive one share of common stock at settlement. After these transactions, she directly held 76,375 shares of common stock, while still holding 11,853 DSUs from a 2024 grant and 8,851 DSUs from a 2025 grant that continue to vest in future installments or earlier if her board service ends.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Shanahan Kathleen M

(Last) (First) (Middle)

C/O GREAT LAKES DREDGE & DOCK CORP.

9811 KATY FREEWAY, SUITE 1200

(Street)

HOUSTON TX 77024

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Great Lakes Dredge & Dock CORP [ GLDD ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
01/15/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	01/15/2026		M		2,849	A	$0	73,373	D
Common Stock	01/15/2026		M		3,002	A	$0	76,375	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Deferred Stock Units	(1)	01/15/2026		M			2,849	(2)	(2)	Common Stock	2,849	$0	11,853	D
Deferred Stock Units	(1)	01/15/2026		M			3,002	(3)	(3)	Common Stock	3,002	$0	8,851	D

Explanation of Responses:

1. Each Deferred Stock Unit ("DSUs") represents the right to receive, at settlement, one share of the Issuer's Common Stock.

2. These DSUs, which were granted in 2024, vest in two equal installments on January 15 of 2026 and 2027 or, if earlier, on the date on which the Reporting Person's board service ends.

3. These DSUs, which were granted in 2025, vest in three equal installments on January 15 of 2026, 2027 and 2028 or, if earlier, on the date on which the Reporting Person's board service ends.

	/s/Vivienne R. Schiffer, by Power of Attorney	01/20/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider activity did GLDD report for director Kathleen M. Shanahan?

Director Kathleen M. Shanahan reported two transactions on January 15, 2026 in which Deferred Stock Units were converted into Great Lakes Dredge & Dock common stock at an exercise price of $0 per share.

How many Great Lakes Dredge & Dock (GLDD) shares did the director acquire?

On January 15, 2026, she acquired 2,849 shares of common stock in one transaction and 3,002 shares in a second transaction, both resulting from the exercise of Deferred Stock Units.

What are Deferred Stock Units (DSUs) in the GLDD Form 4 filing?

Each Deferred Stock Unit (DSU) represents the right to receive, at settlement, one share of Great Lakes Dredge & Dock common stock, as stated in the filing’s explanation of responses.

How many GLDD shares does the director hold after these transactions?

Following the reported transactions, the director directly held 76,375 shares of Great Lakes Dredge & Dock common stock, according to the Form 4 data.

What vesting schedule applies to the 2024 Deferred Stock Units for GLDD?

The DSUs granted in 2024 vest in two equal installments on January 15, 2026 and January 15, 2027, or earlier if the director’s board service ends.

What vesting schedule applies to the 2025 Deferred Stock Units for GLDD?

The DSUs granted in 2025 vest in three equal installments on January 15, 2026, January 15, 2027, and January 15, 2028, or earlier if the director’s board service ends.

Does the GLDD director still hold Deferred Stock Units after the conversion?

Yes. After the January 15, 2026 transactions, the director continued to hold 11,853 DSUs from a 2024 grant and 8,851 DSUs from a 2025 grant, in addition to her common stock holdings.