Great Lakes Dredge SVP granted 18,035 shares

Schiffer Vivienne reported acquisition or exercise transactions in this Form 4 filing.

Rhea-AI Filing Summary

Schiffer Vivienne reported acquisition or exercise transactions in this Form 4 filing.

Great Lakes Dredge & Dock reported that SVP, CLO, CCO & Corporate Secretary Vivienne Schiffer received a grant of 18,035 shares of common stock on May 8, 2025 at no cash cost as part of her compensation, bringing her direct holdings to 82,181 shares. This amended Form 4 corrects an administrative error in the original filing by updating the vesting start date for related restricted stock units from March 15, 2026 to the correct date of May 8, 2026.

Insider Trade Summary

Grant/Award: 18,035 shares

Grant/Award 1 txn

Insider Schiffer Vivienne

Role SVP, CLO, CCO & Corp Secretary

Type	Security	Shares	Price	Value
Grant/Award	Common Stock	18,035	$0.00	$0.00

Holdings After Transaction: Common Stock — 82,181 shares (Direct)

Footnotes (1)

1. F1. This Form 4/A is being filed to correct an administrative error in the original Form 4 filed on May 12, 2025 in which the vesting date for the Restricted Stock Units was inadvertently reported as beginning on March 15, 2026. The correct vesting date begins on May 8, 2026.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did GLDD disclose for Vivienne Schiffer?

Great Lakes Dredge & Dock disclosed that SVP Vivienne Schiffer received a grant of 18,035 shares of common stock on May 8, 2025. The shares were awarded at no cash cost as part of her compensation package.

Why did Great Lakes Dredge & Dock file an amended Form 4 for GLDD?

The company filed an amended Form 4 to correct an administrative error in the original report. The amendment updates the vesting start date for the related restricted stock units to May 8, 2026 instead of March 15, 2026.

How many GLDD shares does Vivienne Schiffer hold after this award?

After the May 8, 2025 grant, Vivienne Schiffer directly holds 82,181 shares of Great Lakes Dredge & Dock common stock. This total reflects the newly awarded 18,035 shares reported in the amended Form 4.

Was the GLDD insider transaction an open-market purchase or sale?

The transaction was not an open-market trade. It was a grant or award of 18,035 shares of Great Lakes Dredge & Dock common stock, given at a reported price of $0.00 per share as compensation.

What specific correction was made in the GLDD Form 4/A footnote?

The footnote explains that the original Form 4 incorrectly stated the restricted stock units would vest beginning March 15, 2026. The amended filing corrects this, stating vesting begins on May 8, 2026 instead.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 03/25/2026 - 04:36 PM Learn about SEC filing dates

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^*

Schiffer Vivienne

(Last) (First) (Middle)

C/O GREAT LAKES DREDGE & DOCK CORP.

9811 KATY FREEWAY, SUITE 1200

(Street)

HOUSTON TEXAS 77024

(City) (State) (Zip)

UNITED STATES

(Country)

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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	SVP, CLO, CCO & Corp Secretary

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/08/2025

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

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

4. If Amendment, Date of Original Filed (Month/Day/Year)
05/12/2025

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	05/08/2025		A		18,035	A	(1)	82,181	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

Explanation of Responses:

1. This Form 4/A is being filed to correct an administrative error in the original Form 4 filed on May 12, 2025 in which the vesting date for the Restricted Stock Units was inadvertently reported as beginning on March 15, 2026. The correct vesting date begins on May 8, 2026.

	Vivienne R. Schiffer	03/25/2026
	** 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.
* Form 4: SEC 1474 (03-26)