-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 AZcET8tPs6s8XXf1lhZR71UEWJmW1UG8fURyCfVKG5nBVsfTsOqJ44EqP2leUrY6
 tvlGjdlkbnVdv6Ylp1xMYQ==

<SEC-DOCUMENT>0001179110-08-016793.txt : 20080915
<SEC-HEADER>0001179110-08-016793.hdr.sgml : 20080915
<ACCEPTANCE-DATETIME>20080915135608
ACCESSION NUMBER:		0001179110-08-016793
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080915
FILED AS OF DATE:		20080915
DATE AS OF CHANGE:		20080915

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Mackie Douglas B
		CENTRAL INDEX KEY:			0001384109

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33225
		FILM NUMBER:		081071176

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		630-574-3000

	MAIL ADDRESS:	
		STREET 1:		C/O GREAT LAKES DREDGE & DOCK CORPORATIO
		STREET 2:		2122 YORK ROAD
		CITY:			OAK BROOK
		STATE:			IL
		ZIP:			60523

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Great Lakes Dredge & Dock CORP
		CENTRAL INDEX KEY:			0001372020
		STANDARD INDUSTRIAL CLASSIFICATION:	HEAVY CONSTRUCTION OTHER THAN BUILDING CONST - CONTRACTORS [1600]
		IRS NUMBER:				205336063
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2122 YORK ROAD
		CITY:			OAK BROOK
		STATE:			IL
		ZIP:			60523
		BUSINESS PHONE:		630-574-3000

	MAIL ADDRESS:	
		STREET 1:		2122 YORK ROAD
		CITY:			OAK BROOK
		STATE:			IL
		ZIP:			60523

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Great Lakes Dredge & Dock Holdings Corp.
		DATE OF NAME CHANGE:	20060808
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-09-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001372020</issuerCik>
        <issuerName>Great Lakes Dredge &amp; Dock CORP</issuerName>
        <issuerTradingSymbol>GLDD</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001384109</rptOwnerCik>
            <rptOwnerName>Mackie Douglas B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>GREAT LAKES DREDGE &amp; DOCK CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>2122 YORK ROAD</rptOwnerStreet2>
            <rptOwnerCity>OAK BROOK</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60523</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-09-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.62</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>344298</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3782</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3782</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3782</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4854</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-09-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.62</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21770</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Common Stock held by the wife of Douglas B. Mackie</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The sales reported were effected pursuant to a Rule 10b5-1 trading plan adopted by Mr. Mackie on March 3, 2008.</footnote>
        <footnote id="F2">Of these shares, 13,853 are represented by restricted stock units.  The restricted stock units vest on May 20, 2011.</footnote>
        <footnote id="F3">Common stock held by the Christopher T. Mackie 1998 Trust.</footnote>
        <footnote id="F4">Common stock held by the Kathleen J. Mackie 1998 Trust.</footnote>
        <footnote id="F5">Common stock held by the Natalie A. Mackie 1998 Trust.</footnote>
        <footnote id="F6">Common stock held by the Madeline C. Mackie 1998 Trust.</footnote>
        <footnote id="F7">Common stock held by Philip D. Mackie directly and by the Philip D. Mackie 1998 Trust.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Douglas B. Mackie</signatureName>
        <signatureDate>2008-09-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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