**EXHIBIT 31.1**

**CERTIFICATIONS PURSUANT TOSECTION 302 OFTHE SARBANES-OXLEY ACT OF 2002**

# **CERTIFICATION**

I, Douglas B. Mackie, ChiefExecutive Officer, certify that:

1.                                       I have reviewed this quarterly report on Form10-Q of Great Lakes Dredge & Dock Corporation;

2.                                       Based on my knowledge, this quarterly reportdoes not contain any untrue statement of a material fact or omit to state amaterial fact necessary to make the statements made, in light of thecircumstances under which such statements were made, not misleading withrespect to the period covered by this quarterly report;

3.                                       Based on my knowledge, the financialstatements, and other financial information included in this quarterly report,fairly present in all material respects the financial condition, results ofoperations and cash flows of the registrant as of, and for, the periodspresented in this quarterly report;

4.                                       The registrant’s other certifying officer andI are responsible for establishing and maintaining disclosure controls andprocedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e))for the registrant and we have:

a)              Designedsuch disclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that materialinformation relating to the registrant, including its consolidatedsubsidiaries, is made known to us by others within those entities, particularlyduring the period in which this quarterly report is being prepared;

b)             Evaluatedthe effectiveness of the registrant’s disclosure controls and procedures andpresented in this quarterly report our conclusions about the effectiveness ofthe disclosure controls and procedures, as of the end of the period covered bythis quarterly report based on such an evaluation; and

c)              Disclosedin this quarterly report any change in the registrant’s internal control overfinancial reporting that occurred during the registrant’s most recent fiscalquarter that has materially affected, or is reasonably likely to materiallyaffect, the registrant’s internal control over financial reporting.

5.                                       The registrant’s other certifying officer andI have disclosed, based on our most recent evaluation of internal control overfinancial reporting, to the registrant’s auditors and the audit committee ofregistrant’s board of directors (or persons performing the equivalentfunction):

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a)              Allsignificant deficiencies and material weaknesses in the design or operation ofinternal control over financial reporting which are reasonably likely toadversely affect the registrant’s ability to record, process, summarize andreport financial information; and

b)             Any fraud, whether or not material, thatinvolves management or other employees who have a significant role in theregistrant’s internal control over financial reporting.
| Date:   November  14, 2006 |                    |
|-------------------------------------------|-------------------------|
|                                      |                    |
|                                      | /s/ Douglas B. Mackie   |   |
|                                      | Douglas B. Mackie       |   |
|                                      | Chief Executive Officer |   |

 

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