<SEC-DOCUMENT>0001140361-14-044608.txt : 20141209
<SEC-HEADER>0001140361-14-044608.hdr.sgml : 20141209
<ACCEPTANCE-DATETIME>20141209175034
ACCESSION NUMBER:		0001140361-14-044608
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20141208
FILED AS OF DATE:		20141209
DATE AS OF CHANGE:		20141209

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TIDEWATER INC
		CENTRAL INDEX KEY:			0000098222
		STANDARD INDUSTRIAL CLASSIFICATION:	WATER TRANSPORTATION [4400]
		IRS NUMBER:				720487776
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0331

	BUSINESS ADDRESS:	
		STREET 1:		601 POYDRAS ST.
		STREET 2:		SUITE 1500
		CITY:			NEW ORLEANS
		STATE:			LA
		ZIP:			70130
		BUSINESS PHONE:		5045681010

	MAIL ADDRESS:	
		STREET 1:		601 POYDRAS ST.
		STREET 2:		SUITE 1500
		CITY:			NEW ORLEANS
		STATE:			LA
		ZIP:			70130

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TIDEWATER MARINE SERVICE INC
		DATE OF NAME CHANGE:	19780724

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Platt Jeffrey
		CENTRAL INDEX KEY:			0001370712

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-06311
		FILM NUMBER:		141276047

	MAIL ADDRESS:	
		STREET 1:		C/O TIDEWATER INC
		STREET 2:		601 POYDRAS STREET, SUITE 1900
		CITY:			NEW ORLEANS
		STATE:			LA
		ZIP:			70130
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-12-08</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000098222</issuerCik>
        <issuerName>TIDEWATER INC</issuerName>
        <issuerTradingSymbol>TDW</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001370712</rptOwnerCik>
            <rptOwnerName>Platt Jeffrey</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O TIDEWATER INC.</rptOwnerStreet1>
            <rptOwnerStreet2>601 POYDRAS ST., SUITE 1500</rptOwnerStreet2>
            <rptOwnerCity>NEW ORLEANS</rptOwnerCity>
            <rptOwnerState>LA</rptOwnerState>
            <rptOwnerZipCode>70130</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>2014-12-08</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>29.6144</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>149350</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1572</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Trustee</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This transaction was executed in multiple trades at prices ranging from $29.60 to $29.62.  The price reported above reflects the weighted average sale price.  Upon request from the SEC staff, the issuer, or a security holder of the issuer, the Reporting Person hereby undertakes to provide the requesting party with full information regarding the number of shares and prices at which the transaction was effected.</footnote>
        <footnote id="F2">Includes 708 shares previously reported as held indirectly through a previous employer's 401(k), which have been rolled into an IRA for the benefit of the Reporting Person since his last Section 16 filing.</footnote>
        <footnote id="F3">Represents shares acquired on a periodic basis and held for the benefit of the Reporting Person by the Trustee of the Tidewater Inc. 401(k) Savings Plan as of November 30, 2014.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Bruce D. Lundstrom as Agent and Attorney-in-Fact for Jeffrey M. Platt</signatureName>
        <signatureDate>2014-12-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
