<SEC-DOCUMENT>0001567619-19-010441.txt : 20190510
<SEC-HEADER>0001567619-19-010441.hdr.sgml : 20190510
<ACCEPTANCE-DATETIME>20190510170036
ACCESSION NUMBER:		0001567619-19-010441
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190509
FILED AS OF DATE:		20190510
DATE AS OF CHANGE:		20190510

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BATES THOMAS R JR
		CENTRAL INDEX KEY:			0001230117

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-06311
		FILM NUMBER:		19815801

	MAIL ADDRESS:	
		STREET 1:		TETRA TECHNOLOGIES, INC.
		STREET 2:		24955 INTERSTATE 45 N
		CITY:			THE WOODLANDS
		STATE:			TX
		ZIP:			77380

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:			1231

	BUSINESS ADDRESS:	
		STREET 1:		6002 ROGERDALE ROAD
		STREET 2:		SUITE 600
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77072
		BUSINESS PHONE:		7134705300

	MAIL ADDRESS:	
		STREET 1:		6002 ROGERDALE ROAD
		STREET 2:		SUITE 600
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77072

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TIDEWATER MARINE SERVICE INC
		DATE OF NAME CHANGE:	19780724
</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>2019-05-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001230117</rptOwnerCik>
            <rptOwnerName>BATES THOMAS R JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O TIDEWATER INC.</rptOwnerStreet1>
            <rptOwnerStreet2>6002 ROGERDALE ROAD, SUITE 600</rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77072</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-05-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>23.1064</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>27141</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This transaction was executed in multiple trades at prices ranging from $22.93 to $23.34. 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>
    </footnotes>

    <ownerSignature>
        <signatureName>Bruce D. Lundstrom as Agent and Attorney-in-Fact for Thomas R. Bates, Jr.</signatureName>
        <signatureDate>2019-05-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
