Director tenders 8,436 GLDD (NASDAQ: GLDD) shares at $17 cash in merger

Rhea-AI Filing Summary

Great Lakes Dredge & Dock Corporation director Dana A. Armstrong disposed of 8,436 shares of common stock in connection with the company’s merger with Saltchuk Resources. The shares were tendered pursuant to a merger agreement under which each outstanding GLDD share was cancelled and converted into the right to receive $17.00 in cash, without interest and subject to tax withholding. Following this tender-offer disposition, Armstrong reported holding no direct GLDD shares.

Insights

Equity compensation & M&A specialist

Director’s stake cashed out via all-share cash merger.

The filing shows director Dana A. Armstrong tendered 8,436 GLDD common shares in a merger where each outstanding share was converted into the right to receive $17.00 in cash. This is a transaction driven by a corporate acquisition, not open-market trading.

After the tender-offer disposition, Armstrong reported 0 shares held directly, meaning her reported equity position in GLDD common stock was fully cashed out at the merger closing. The transaction reflects completion of the Saltchuk Resources acquisition rather than a discretionary portfolio decision by the director.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Armstrong Dana A

Role Director

Type	Security	Shares	Price	Value
U	Common Stock	8,436	$0.00	--

Holdings After Transaction: Common Stock — 0 shares (Direct)

Footnotes (1)

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Key Figures

Shares disposed: 8,436 shares Cash consideration per share: $17.00 per share Shares held after transaction: 0 shares +2 more

5 metrics

Shares disposed 8,436 shares Common stock tendered pursuant to merger

Cash consideration per share $17.00 per share Each outstanding GLDD share at merger effective time

Shares held after transaction 0 shares Director’s reported direct GLDD holdings post‑merger

Transaction type Tender-offer disposition Form 4 code U, non-derivative common stock

Merger effective time April 1, 2026 Date Merger Sub merged into GLDD

Key Terms

Agreement and Plan of Merger, tender offer, wholly owned subsidiary, Merger Sub, +1 more

5 terms

Agreement and Plan of Merger regulatory

"Pursuant to the Agreement and Plan of Merger (the "Merger Agreement"), dated February 10, 2026"

An Agreement and Plan of Merger is a formal document where two companies agree to combine into one, outlining how the process will happen. It’s like a step-by-step plan for merging, and it matters because it shows both sides have agreed on the details before the official transition takes place.

tender offer financial

"transaction_code_description": "Disposition pursuant to a tender offer""

A tender offer is a proposal made by a person or company to buy shares from existing shareholders at a set price, usually higher than the current market value, within a specific time frame. It matters to investors because it can lead to a change in ownership or control of a company, and shareholders must decide whether to sell their shares at the offered price.

wholly owned subsidiary financial

"Issuer surviving as a wholly owned subsidiary of Parent upon consummation"

A wholly owned subsidiary is a company whose entire ownership is held by another company (the parent), so the parent controls decisions, operations, and finances. Think of it as a fully controlled branch that runs as its own legal entity but whose results flow straight into the parent’s financial statements; investors watch these structures because they affect consolidated revenue, risk exposure, and how profits, liabilities, and cash flow are allocated across the corporate group.

Merger Sub regulatory

"Huron MergeCo, Inc. ("Merger Sub"), and Great Lakes Dredge & Dock Corporation"

A merger sub is a temporary, wholly owned subsidiary that an acquiring company creates to carry out a merger with another firm. Think of it as a wrapper used to combine two businesses—this can simplify legal and tax steps, isolate liabilities, and help preserve the target’s contracts or stock structure, so investors watch it because the chosen approach affects deal mechanics, shareholder votes, potential dilution, and legal or tax risk.

cash, without interest financial

"converted into the right to receive $17.00 in cash, without interest"

Form 4 Insider Transactions: What Each Field Means →

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

X

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^*

Armstrong Dana A

(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)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/01/2026

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)

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	04/01/2026		U		8,436	D	(1)	0	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. 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.

	/s/Vivienne R. Schiffer, by Power of Attorney	04/01/2026
	** 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)

FAQ

What did GLDD director Dana A. Armstrong report on this Form 4 for GLDD?

Dana A. Armstrong reported a tender-offer disposition of 8,436 shares of Great Lakes Dredge & Dock common stock. The shares were cashed out as part of the merger with Saltchuk Resources at $17.00 per share, and her reported direct holdings fell to zero.

How many Great Lakes Dredge & Dock (GLDD) shares were disposed of in this insider filing?

The Form 4 shows a disposition of 8,436 shares of GLDD common stock. These shares were not sold on the open market; they were tendered and cancelled in exchange for a $17.00 cash payment per share under the merger terms.

What price did GLDD shareholders, including the director, receive per share in the merger?

Each outstanding share of Great Lakes Dredge & Dock common stock was converted into the right to receive $17.00 in cash. This cash consideration applied to all shares outstanding at the effective time of the merger, subject to any required tax withholdings.

What happened to Dana A. Armstrong’s GLDD holdings after the tender-offer disposition?

After tendering 8,436 shares in the merger, Dana A. Armstrong reported holding 0 shares of GLDD common stock directly. Her position was fully converted into cash at $17.00 per share when the merger closed and the shares were cancelled.

What corporate event drove the GLDD Form 4 transaction reported by Dana A. Armstrong?

The transaction was triggered by a merger where Huron MergeCo, Inc. merged into Great Lakes Dredge & Dock, making GLDD a wholly owned subsidiary of Saltchuk Resources. At the effective time, all outstanding GLDD shares were cancelled for $17.00 cash per share.