$17-per-share deal takes Great Lakes (GLDD) private under Saltchuk

Rhea-AI Filing Summary

Great Lakes Dredge & Dock SVP Eleni Beyko reported merger-related stock changes. On April 1, 2026, she acquired 25,505 shares of common stock as a grant or award, then all 151,312 directly held shares were disposed of pursuant to a tender offer in connection with the company’s merger.

Under the Merger Agreement with Saltchuk Resources’ Huron MergeCo, each share of Great Lakes Dredge & Dock common stock was cancelled at the effective time and converted into the right to receive $17.00 in cash, without interest and subject to tax withholdings. Footnotes state certain performance-based restricted stock units fully vested under the Merger Agreement, while 61,359 RSUs were cashed out at the merger price and 15,769 RSUs were replaced by an equivalent-value cash-based award with the same time-based vesting terms.

Insights

Equity compensation and M&A specialist

Insider’s equity was mechanically converted to cash in a closing merger.

The transactions show SVP Eleni Beyko receiving 25,505 common shares as a compensation grant, then tendering 151,312 shares into the cash merger at $17.00 per share. This reflects deal mechanics rather than discretionary open-market trading.

Footnotes clarify performance-based awards fully vested at the effective time, 61,359 RSUs were cashed out at the merger consideration, and 15,769 RSUs became cash-based awards with the same vesting schedule. Overall, this Form 4 mainly confirms how her equity was treated when Great Lakes Dredge & Dock became a wholly owned subsidiary of Saltchuk Resources.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider BEYKO ELENI

Role SVP - Offshore Energy

Type	Security	Shares	Price	Value
Grant/Award	Common Stock	25,505	$0.00	--
U	Common Stock	151,312	$0.00	--

Holdings After Transaction: Common Stock — 151,312 shares (Direct)

Footnotes (1)

1. Pursuant to the Merger Agreement (as defined in footnote 2 below), at the Effective Time (as defined in footnote 2 below), these performance-based restricted stock units fully vested, with the number earned or deemed earned as set forth in the Merger Agreement. 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 ("Common Stock") was cancelled and converted into the right to receive $17.00 in cash (the "Merger Consideration"), without interest and subject to any required tax withholdings. Includes 77,128 restricted stock units ("RSUs"). At the Effective Time, 61,359 outstanding RSUs were canceled and converted into the right to receive an amount in cash equal to the product of the aggregate number of shares of Common Stock underlying such RSUs immediately prior to the Effective Time, multiplied by the Merger Consideration, and 15,769 RSUs were replaced by a cash-based award of equivalent value (based on the Offer Price (as defined in the Merger Agreement)) that is subject to the same time-based vesting conditions as applied to the unvested portion of such award prior to the Effective Time.

Key Figures

Shares granted: 25,505 shares Shares tendered: 151,312 shares Merger consideration: $17.00 per share +3 more

6 metrics

Shares granted 25,505 shares Common stock grant to SVP Eleni Beyko on April 1, 2026

Shares tendered 151,312 shares Common stock disposed of pursuant to tender offer in merger

Merger consideration $17.00 per share Cash paid for each Great Lakes Dredge & Dock common share

Total RSUs held 77,128 RSUs Restricted stock units referenced as part of Beyko’s holdings

RSUs cashed out 61,359 RSUs Cancelled and paid in cash based on the $17.00 merger price

RSUs converted to cash award 15,769 RSUs Replaced by cash-based award with same time-based vesting

Key Terms

performance-based restricted stock units, Agreement and Plan of Merger, Merger Consideration, restricted stock units ("RSUs"), +1 more

5 terms

performance-based restricted stock units financial

"these performance-based restricted stock units fully vested, with the number earned or deemed earned"

Performance-based restricted stock units are a type of employee equity award that converts into company shares only if predefined financial or operational targets are met over a set period. Think of it like a bonus check that becomes stock only when specific goals are hit; it ties pay to results, aligning managers’ incentives with shareholders. Investors care because these awards affect future share count, executive incentives, and signal how management’s success will be measured and rewarded.

Agreement and Plan of Merger financial

"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.

Merger Consideration financial

"converted into the right to receive $17.00 in cash (the "Merger Consideration")"

Merger consideration is the total payment a company or buyer offers to shareholders of a target company in exchange for combining the two businesses, and can include cash, shares in the surviving company, debt assumption, or a mix of these. Investors care because the form and amount affect the deal’s value, tax consequences, immediate cash received versus future ownership, and the risk and upside of holding new shares — similar to choosing between cash now or stock that could grow later.

restricted stock units ("RSUs") financial

"Includes 77,128 restricted stock units ("RSUs"). At the Effective Time, 61,359 outstanding RSUs were canceled"

Restricted stock units (RSUs) are a company promise to give an employee shares of stock (or cash equivalent) in the future, but only after certain conditions—usually staying with the company for a set time or hitting performance goals—are met. Investors watch RSUs because when they vest they increase the number of shares outstanding and can lead insiders to sell shares, affecting share price, company dilution and the true cost of employee pay.

cash-based award financial

"15,769 RSUs were replaced by a cash-based award of equivalent value"

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
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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^*

BEYKO ELENI

(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 - Offshore Energy

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		A(1)		25,505(1)	A	(1)	151,312	D
Common Stock	04/01/2026		U		151,312(2)(3)	D	(2)	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 Merger Agreement (as defined in footnote 2 below), at the Effective Time (as defined in footnote 2 below), these performance-based restricted stock units fully vested, with the number earned or deemed earned as set forth in the Merger Agreement.

2. 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 ("Common Stock") was cancelled and converted into the right to receive $17.00 in cash (the "Merger Consideration"), without interest and subject to any required tax withholdings.

3. Includes 77,128 restricted stock units ("RSUs"). At the Effective Time, 61,359 outstanding RSUs were canceled and converted into the right to receive an amount in cash equal to the product of the aggregate number of shares of Common Stock underlying such RSUs immediately prior to the Effective Time, multiplied by the Merger Consideration, and 15,769 RSUs were replaced by a cash-based award of equivalent value (based on the Offer Price (as defined in the Merger Agreement)) that is subject to the same time-based vesting conditions as applied to the unvested portion of such award prior to the Effective Time.

	/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.
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* Form 4: SEC 1474 (03-26)