Tidewater, Inc.

Item Entry into a Material Definitive Agreement. 1.01 On September 21, 2026, Tidewater Inc., a Delaware corporation (“Tidewater” or the “Company”) entered into a Guarantee Agreement with Banco Nacional de Desenvolvimento Econômico e Social (“BNDES”). Pursuant to the Guarantee Agreement, the Company agrees to guarantee the full and timely payment when due and payable of all of the borrower’s obligations under the BNDES Construction Loans (as defined below). Tidewater’s guarantee constitutes its unsecured obligations and, subject to certain limitations, ranks pari passu in priority of payment with all of its other unsecured and unsubordinated obligations. The BNDES Construction Loans consist of the loan facilities under the Credit Facility Agreements Nos. 07.2.0417.1, 07.2.0418.1, 10.2.1621.1, 12.2.0433.1, and 12.2.0434.1 (collectively, the “BNDES Construction Loans”), entered into between 2007 and 2012 and as amended from time to time, by and between BNDES, as lender, Wilson Sons Offshore S.A. (now known as Tidewater do Brasil S.A., “WSO”), an indirect wholly owned subsidiary of the Company, as borrower, and Wilson Sons S.A. (“Wilson Sons”) and/or Remolcadores Ultratug Limitada (“Remolcadores”), as guarantors. The Company is currently working with BNDES to finalize the documentation for releasing Wilson Sons and Remolcadores as guarantors of the BNDES Construction Loans. See the Company’s Current Report on Form 8-K filed with the Securities and Exchange Commission on August 31, 2026 for further information about the BNDES Construction Loans. The foregoing summary of the Guarantee Agreement is subject to, and qualified in its entirety by, the text of the Guarantee Agreement, a copy of which is filed as Exhibit 10.1 hereto, the terms of which are incorporated herein by reference.

Item Creation of a Direct Financial Obligation 2.03 or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information set forth under Item 1.01 above is incorporated into this Item 2.03 by reference as if fully set forth under this item.