Exhibit 10.1

FIRST AMENDMENT
TO
INTERNATIONAL LETTER OF CREDIT AGREEMENT

THIS FIRST AMENDMENT TO INTERNATIONAL LETTER OF CREDIT AGREEMENT is dated as of the 16 th  day of July, 2007 (this “ First Amendment ”), and entered into among GREAT LAKES DREDGE & DOCK CORPORATION, a Delaware corporation (the “ Borrower ”), GREAT LAKES DREDGE & DOCK COMPANY, LLC, a Delaware limited liability company (the “ Guarantor ”), and WELLS FARGO HSBC TRADE BANK, N.A. (the “ Bank ”).

BACKGROUND:

A.            The Borrower, the Guarantor and Bank entered into an International Letter of Credit Agreement, dated as of September 29, 2006 (the “ Agreement ”).  Unless specifically defined or redefined below, capitalized terms used herein shall have the meanings ascribed thereto in the Agreement.

B.            The Borrower has requested an amendment to the Agreement.

C.            The Bank hereby agrees to amend the Agreement, subject to the terms and conditions set forth herein.

NOW, THEREFORE, in consideration of the covenants, conditions and agreements hereafter set forth, and for other good and valuable consideration, the receipt and adequacy of which are all hereby acknowledged, the Borrower, the Guarantor and the Bank covenant and agree as follows:

SECTION 1.  AMENDMENTS .

(a)           Amendment to Section 2.1(a) .  Section 2.1(a) of the Agreement is hereby amended and restated to read as follows:

(a)           Upon the terms and conditions and relying upon the representations and warranties herein set forth, the Bank agrees to issue standby Letters of Credit for the account of the Borrower up to an aggregate face amount not exceeding at any one time outstanding the lesser of (i) $24,000,000.00 (such amount, as it may be reduced from time to time pursuant to Section 3.6 , being the Bank’s “ Commitment ”) or (ii) the International Borrowing Base.

(b)           Amendment to Section 4.1 .  Section 4.1 of the Agreement is hereby amended and restated to read as follows:

Facility Fee .  The Borrower shall pay to the Bank (i) on July 16, 2007, a non-refundable facility fee in an amount equal to the product of (x) $4,000,000 and (y) the Annual Facility Fee Percentage, prorated for the period of time from July 16, 2007, through the Loan Facility Anniversary Date, and (ii) on each Loan Facility Anniversary Date (other than the Maturity Date), a non-refundable facility fee in an amount equal to the product of (x) the Commitment and (y) the Annual Facility Fee Percentage.

(c)           Amendment to Section 9.5 .  Section 9.5 of the Agreement is hereby amended and restated to read as follows:

9.5           Financial Covenants

(a)           Maximum Total Leverage . The Borrower and its consolidated Subsidiaries shall not permit the ratio (the “ Total Leverage Ratio ”) of (i) the aggregate unpaid principal amount of Total Funded Debt as of the last day of any Fiscal Quarter ending during the periods described below to (ii) Adjusted Consolidated EBITDA for the four (4) consecutive Fiscal Quarter period ending as of such date, to exceed the corresponding ratio set forth below opposite such period:

(b)           Interest Coverage Ratio .  The Borrower and its consolidated Subsidiaries shall not permit the ratio (the “ Interest Coverage Ratio ”) of (i) Adjusted Consolidated EBITDA for any four (4) consecutive Fiscal Quarter period ending as of the last day of any Fiscal Quarter ending during the periods described below to (ii) Interest Expense for such period ending as of such date, to be less than the corresponding ratio set forth below opposite such period:

(d)           Amendment to Section 10.1(n)   Section 10.1(n) of the Agreement is hereby amended and restated to read as follows:

(n)           Change of Control .              A change in control pursuant to Section 7.1(j) (or such comparable section)  of the Domestic Credit Agreement shall occur; or

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(e)           Amendments to Exhibit “A” of the Agreement .  (i)  The following definitions in Exhibit “A” of the Agreement are hereby amended and restated in their entirety, to read as follows:

“ Adjusted Consolidated EBITDA ” means EBITDA adjusted as required or permitted by Regulation S-X of the 1933 Act, but in any event in a manner consistent with the Borrower’s applicable filings submitted with the Securities and Exchange Commission.

“ Domestic Credit Agreement ” shall mean the Credit Agreement dated as of June 12, 2007, among the Borrower, the other Loan Parties from time to time party thereto, the financial institutions from time to time party thereto and LaSalle Bank National Association, as Administrative Agent, Swing Line Lender and an Issuing Lender, as the same may be amended, restated, supplemented, modified, refunded, refinanced or replaced, in whole or in part, from time to time.

“ Domestic Lenders ” shall mean LaSalle Bank National Association, as administrative agent, and other agents, arrangers and lenders now or hereafter party to the Domestic Credit Agreement.

“ EBITDA ” means, with respect to any period, as determined in accordance with GAAP, the sum of the amounts for such period of Net Income, (a) plus , without duplication and to the extent reflected as a charge in the consolidated statement of such Net Income for such period: (i) depreciation, depletion and amortization expense, (ii) federal, state, local and foreign income taxes, (iii) Interest Expense, (iv) transaction fees and expenses incurred in connection with the Transactions (as defined in the Domestic Credit Agreement) to the extent not capitalized and to the extent not exceeding in the aggregate $3,000,000, (v) non-cash charges and losses (excluding any such non-cash charges or losses to the extent (x) there were cash charges with respect to such charges and losses in past accounting periods or (y) there is a reasonable expectation that there will be cash charges with respect to such charges and losses in future accounting periods), (vi) any amounts included in the calculation of Net Income for amortization or non-cash charges for the write-off or impairment of goodwill, intangibles or other purchase accounting adjustments related to the accounting for the Transactions or other acquisitions under GAAP (including Financial Accounting Standards No. 141 and 142), (vii) fees and expenses incurred in connection with the Bonding Agreement (as defined in the Domestic Credit Agreement) and the Equipment Financing Debt (as defined in the Domestic Credit Agreement), (viii) Net Income attributable to the minority equity interest in NASDI (as defined in the Domestic Credit Agreement) that is not

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owned by the Borrower to the extent the Net Income in respect of such minority equity interest is received by the Borrower and (ix) transaction fees and expenses incurred in connection with the acquisition of the vessels Ohio and Terrapin Island to the extent not capitalized, and (b) minus , without duplication, (i) non-cash gains (excluding any such non-cash gains to the extent (x) there were cash gains with respect to such gains in past accounting periods or (y) there is a reasonable expectation that there will be cash gains with respect to such gains in future accounting periods) and (ii) Net Income attributable to the minority equity interest in NASDI that is not owned, directly or indirectly, by the Borrower to the extent the Net Income in respect of such minority equity interest is distributed to the holder or holders of such minority equity interest and (c) plus , without duplication, cash dividends received by the Borrower or any Subsidiary fro