Great Lakes Dredge & Dock Corp SEC Filings

Great Lakes Dredge & Dock Corp ownership filing shows Vanguard Capital Management reports beneficial ownership of 3,356,323 shares of Common Stock, representing 5.02% of the class. The filing discloses sole dispositive power over 3,356,323 shares and sole voting power over 500,165 shares. The filing is signed on 04/30/2026.

BlackRock, Inc. filed an Amendment No. 17 to Schedule 13G/A reporting beneficial ownership of $5,467,592 shares of Great Lakes Dredge & Dock CORP as of 03/31/2026, representing 8.2% of the class.

The filing states BlackRock's Reporting Business Units hold 5,306,560 shares with sole voting power and 5,467,592 shares with sole dispositive power. The ownership is reported on behalf of BlackRock's business units in accordance with SEC Release No. 34-39538.

Great Lakes Dredge & Dock Corp ownership update: Dimensional Fund Advisors reports beneficial ownership of 3,386,372 shares, representing 5.1% of the company's common stock. The filing states Dimensional has sole voting power for 3,347,197 shares and sole dispositive power for 3,386,372 shares, and disclaims beneficial ownership because the shares are owned by client funds.

The filing explains these shares are held by multiple registered investment funds advised or sub‑advised by Dimensional; no single fund is known to exceed 5% of the class. The report is an amendment to a prior Schedule 13G.

Great Lakes Dredge & Dock Corporation SVP, CLO, CCO & Corporate Secretary Vivienne Schiffer reported equity changes tied to the company’s merger with Saltchuk Resources. On April 1, 2026, she acquired 28,945 shares of common stock at $0.00 per share through a grant or award, reflecting the vesting of performance-based restricted stock units under the merger terms.

That same day, 144,817 common shares held directly were disposed of in a tender-offer transaction, leaving her with 0 directly owned shares after the merger closed. Under the merger agreement, each Great Lakes share was cancelled and converted into the right to receive $17.00 in cash.

The filing notes prior holdings included 71,357 restricted stock units. At the effective time, 52,855 RSUs were cancelled for a cash payment based on the $17.00 merger consideration, while 18,502 RSUs were replaced with a cash-based award of equivalent value that keeps the original time-based vesting schedule.

Great Lakes Dredge & Dock CEO Lasse Petterson reported merger-related equity transactions. He was granted 206,445 shares of common stock at no cost upon full vesting of performance-based restricted stock units at the merger’s effective time, as specified in the Merger Agreement.

On the same date, 1,568,290.29 directly held shares of common stock were disposed of pursuant to a tender offer when Saltchuk’s merger subsidiary combined with the company, with each share converted into the right to receive $17.00 in cash, subject to tax withholding. Following this disposition, Petterson reported no directly held common shares.

The filing notes 503,878 restricted stock units in total, of which 375,541 RSUs were cancelled in exchange for cash equal to the underlying shares multiplied by the $17.00 merger consideration, while 128,337 RSUs were replaced by a cash-based award of equivalent value that keeps the original time-based vesting schedule.

Great Lakes Dredge & Dock SVP & CFO Scott Lee Kornblau reported equity changes tied to the company’s cash merger with Saltchuk Resources. On April 1, 2026, performance-based restricted stock units fully vested, resulting in an acquisition of 90,518 shares of common stock at no cost.

At the merger’s effective time, each share of Great Lakes common stock was cancelled and converted into the right to receive $17.00 in cash. Kornblau’s 244,126.24 directly held shares were disposed of pursuant to the tender offer, reducing his direct common stock holdings to zero.

The filing notes 149,614 restricted stock units, of which 123,910 RSUs were cancelled for cash based on the $17.00 merger consideration, while 25,704 RSUs were replaced with a cash-based award of equivalent value that keeps the same time-based vesting schedule.

Great Lakes Dredge & Dock Corporation SVP David Johanson reported mixed equity transactions tied to the company’s sale to Saltchuk Resources. On April 1, 2026, performance-based restricted stock units fully vested and 71,860 shares of common stock were acquired at no cost, reflecting equity awards settling at the merger’s effective time.

That same day, 191,597.5164 shares of common stock were disposed of in a transaction labeled as a tender-offer disposition, as each outstanding share of Great Lakes common stock was cancelled and converted into the right to receive $17.00 in cash, subject to tax withholding. After this cash-out, Johanson reported 0 common shares directly owned.

In a separate award-related transaction on March 25, 2026, he acquired 521.257 shares of common stock at $10.821 per share under the company’s 2025 Employee Stock Purchase Plan, which prices purchases at 85% of the closing price on a specified date. Footnotes also note that large blocks of restricted stock units were either converted into cash at the $17.00 merger consideration or replaced by equivalent cash-based awards with the same time-based vesting conditions.

Great Lakes Dredge & Dock Corporation senior vice president of market development William H. Hanson reported equity award and merger-related share activity. On April 1, 2026, his performance-based restricted stock units fully vested under the merger agreement, and his common shares were converted into cash at $17.00 per share.

The filing notes 33,233 restricted stock units in total, of which 24,785 were cancelled for a cash payment based on the $17.00 merger price and 8,448 were converted into a cash-based award with the same time-based vesting terms. Following the tender-offer related disposition, the Form 4 shows no remaining common stock directly held.