**EXHIBIT 31.1**

 

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

 

**CERTIFICATION**

 

I, Douglas B. Mackie, Chief Executive Officer, certify that:

 

1.                                       I have reviewedthis quarterly report on Form 10-Q of Great Lakes Dredge & Dock Corporation;

 

2.                                       Based on myknowledge, this quarterly report does not contain any untrue statement of amaterial fact or omit to state a material fact necessary to make the statementsmade, in light of the circumstances under which such statements were made, not misleadingwith respect to the period covered by this quarterly report;

 

3.                                       Based on myknowledge, the financial statements, and other financial information includedin this quarterly report, fairly present in all material respects the financialcondition, results of operations and cash flows of the registrant as of, andfor, the periods presented in this quarterly report;

 

4.                                       Theregistrant’s other certifying officer and I are responsible for establishingand maintaining disclosure controls and procedures (as defined in Exchange ActRules 13a-15(e) and 15d-15(e)) for the registrant and we have:

 

a)              Designed such disclosurecontrols and procedures, or caused such disclosure controls and procedures tobe designed under our supervision, to ensure that material information relatingto the registrant, including its consolidated subsidiaries, is made known to usby others within those entities, particularly during the period in which thisquarterly report is being prepared;

 

b)             Evaluated the effectivenessof the registrant’s disclosure controls and procedures and presented in thisquarterly report our conclusions about the effectiveness of the disclosurecontrols and procedures, as of the end of the period covered by this quarterlyreport based on such an evaluation; and

 

c)              Disclosed in this quarterlyreport any change in the registrant’s internal control over financial reportingthat occurred during the registrant’s most recent fiscal quarter that hasmaterially affected, or is reasonably likely to materially affect, theregistrant’s internal control over financial reporting.

 

5.                                       Theregistrant’s other certifying officer and I have disclosed, based on our mostrecent evaluation of internal control over financial reporting, to theregistrant’s auditors and the audit committee of registrant’s board ofdirectors (or persons performing the equivalent function):

 

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a)              All significant deficienciesand material weaknesses in the design or operation of internal control overfinancial reporting which are reasonably likely to adversely affect theregistrant’s ability to record, process, summarize and report financialinformation; and

 

b)             Any fraud, whether or notmaterial, that involves management or other employees who have a significantrole in the registrant’s internal control over financial reporting.

 

 
| Date:      August 12,  2004 |
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|                                                           |
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|                                                           | /s/  Douglas B. Mackie |   |
|                                                           | Douglas B. Mackie |   |
|                                                           | Chief Executive Officer |   |

 

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