This Amendment No. 2 to the Tender Offer Statement on Schedule TO (this “Amendment”)
amends and supplements the Tender Offer Statement on Schedule TO filed with the U.S. Securities and Exchange Commission on March 4, 2026 (as it may be further amended or supplemented from time to time, the “Schedule TO”),
with respect to the cash tender offer (the “Offer”) made by Huron MergeCo., Inc., a Delaware corporation (“Purchaser”) and a wholly owned subsidiary of Saltchuk Resources, Inc., a Washington corporation
(“Parent”), to purchase all of the issued and outstanding shares of Common Stock, par value $0.0001 per share (the “Shares”), of Great Lakes Dredge & Dock Corporation (“GLDD”),
pursuant to the Agreement and Plan of Merger, dated as of February 10, 2026, by and among Parent, Purchaser, and GLDD (as it may be amended or supplemented from time to time, the “Merger Agreement”), for $17.00 per Share, net
to the seller thereof in cash, without interest, subject to any required tax withholdings (such consideration as it may be amended from time to time pursuant to the terms of the Merger Agreement), upon the terms and subject to the conditions set
forth in the Offer to Purchase, dated March 4, 2026 (together with any amendments or supplements thereto, the “Offer to Purchase”), and in the related Letter of Transmittal (together with any amendments or supplements
thereto, the “Letter of Transmittal”), copies of which are attached to the Schedule TO as Exhibits (a)(1)(A) and (a)(1)(B), respectively, as each may be amended or supplemented from time to time.
Except as otherwise set forth in this Amendment, the information set forth in the Schedule TO remains unchanged. This Amendment is being filed to reflect
certain updates as reflected below. Capitalized terms used but not otherwise defined herein have the meanings ascribed thereto in the Offer to Purchase or the Schedule TO, as applicable. You should read this Amendment together with the Schedule TO
and the Offer to Purchase.
ITEMS 1 THROUGH 11.
The
information set forth in the Offer to Purchase under Section 16—“Certain Legal Matters; Regulatory Approvals; Appraisal Rights” and Items 1 through 11 of the Schedule TO, to the extent such Items incorporate by reference the
information contained in the Offer to Purchase, are hereby amended and supplemented by deleting the paragraph of the subsection titled “Litigation” and adding the following paragraphs in its place:
“As of March 23, 2026, three complaints were filed in state court by purported stockholders of GLDD regarding the Transactions (the
“Complaints”). On March 9, 2026, Steven Weiss, a purported stockholder of GLDD, filed a complaint in the Supreme Court of the State of New York, County of New York, against GLDD and the GLDD Board, captioned Weiss v. Great
Lakes Dredge & Dock Corporation, et al., Index No. 651452/2026 (the “Weiss Complaint”). The Weiss Complaint alleges that the Schedule 14D-9 misrepresents
and/or omits material information and, as a result, asserts causes of action against all defendants for (i) negligent misrepresentation and concealment in violation of New York common law and (ii) negligence in violation of New York common
law. The Weiss Complaint seeks, among other things, (i) injunctive relief preventing the consummation of the Transactions; (ii) rescission or actual and punitive damages in the event the Transactions are consummated; and (iii) an
award of plaintiff’s fees and expenses, including attorneys’ and experts’ fees.
On March 10, 2026, Matthew Hamilton, a purported
stockholder of GLDD, filed a complaint in the Supreme Court of the State of New York, County of New York, against GLDD and the GLDD Board, captioned Hamilton v. Great Lakes Dredge & Dock Corporation, et al., Index
No. 651461/2026 (the “Hamilton Complaint”). The Hamilton Complaint alleges that the Schedule 14D-9 misrepresents and/or omits material information and, as a result, asserts causes of
action against all defendants for (i) negligent misrepresentation and concealment in violation of New York common law and (ii) negligence in violation of New York common law. The Hamilton Complaint seeks, among other things,
(i) injunctive relief preventing the consummation of the Transactions; (ii) rescission or actual and punitive damages in the event the Transactions are consummated; and (iii) an award of plaintiff’s fees and expenses, including
attorneys’ and experts’ fees.
On March 13, 2026, Robert Garfield and Anthony Zaccagnino, purported stockholders of GLDD, filed a
complaint in the Supreme Court of the State of New York, County of Westchester, against GLDD, the GLDD Board, Purchaser, Parent, and Guggenheim Securities, captioned Garfield and Zaccagnino v. Armstrong, et al., Index No. 59413/2026
(the “Garfield Complaint”). The Garfield Complaint alleges, among other things, that this Schedule TO and the Schedule 14D-9 misrepresent and/or omit material information and, as a
result, asserts
