Dana A. Armstrong - 01 Apr 2026 Form 4 Insider Report for Great Lakes Dredge & Dock CORP (GLDD)

Reporting relationship: Director
Issuer ticker: GLDD
Reported as of: 01 Apr 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 01 Apr 2026, 15:53:18 UTC
Prior SEC filing: 02 Apr 2026
Source filing: View source filing
Reporting owner signature: /s/Vivienne R. Schiffer, by Power of Attorney

Key filing fact

Dana A. Armstrong filed Form 4 for Great Lakes Dredge & Dock CORP (GLDD) on 01 Apr 2026.

Key facts

This page summarizes Dana A. Armstrong's Form 4 filing for Great Lakes Dredge & Dock CORP (GLDD).
1 reported transaction and 0 derivative rows are listed below.
Accepted by SEC: 01 Apr 2026, 15:53.

Change

Previous filing in this sequence was filed on 02 Apr 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001907154 Primary reporting owner

Armstrong Dana A

Relationship: Director
Address: C/O GREAT LAKES DREDGE & DOCK CORP.,, 9811 KATY FREEWAY, SUITE 1200, HOUSTON
Signature: /s/Vivienne R. Schiffer, by Power of Attorney
Signature date: 01 Apr 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

GLDD transaction

Common Stock

Disposition pursuant to a tender of shares in a change of control transaction

Transaction value
Shares: -8,436
Change %: -100%
Price
Shares after: 0
Date: 01 Apr 2026
Ownership: Direct
Footnotes: F1

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Section 16 status

Dana A. Armstrong is no longer subject to Section 16 filing requirements. Form 4 or Form 5 obligations may still apply in specific circumstances.

Explanation of responses 1 footnote

Footnote F1

Pursuant to the Agreement and Plan of Merger (the "Merger Agreement"), dated February 10, 2026, by and among Saltchuk Resources, Inc. ("Parent"), Huron MergeCo, Inc. ("Merger Sub"), and Great Lakes Dredge & Dock Corporation ("Issuer") on April 1, 2026 (the "Effective Time"), Merger Sub merged with and into Issuer, with Issuer surviving as a wholly owned subsidiary of Parent upon consummation of the transactions contemplated by the Merger Agreement. At the Effective Time, each outstanding share of common stock of the Issuer was cancelled and converted into the right to receive $17.00 in cash, without interest and subject to any required tax withholdings.