Material Event (Form 8-K)

As previously disclosed, on April 22, 2026, Helix Energy Solutions Group, Inc., a Minnesota corporation ("Parent"), Odyssey Sub, Inc., a Delaware corporation and direct, wholly owned subsidiary of Parent ("Parent Sub"), Hercules Sub LLC, a Delaware limited liability company and direct, wholly owned subsidiary of Parent ("LLC Sub"), and Hornbeck Offshore Services, Inc., a Delaware corporation (the "Company") entered into an Agreement and Plan of Merger (the "Merger Agreement"), pursuant to which, upon the terms and subject to the conditions set forth therein, (i) Parent Sub will merge with and into the Company, with the Company continuing as the surviving entity (the "Surviving Corporation") (the "First Company Merger") and (ii) immediately following the First Company Merger, the Surviving Corporation will merge with and into LLC Sub (the "Second Company Merger" and, together with the First Company Merger, the "Mergers"), with LLC Sub continuing as the surviving entity.

On June 11, 2026, the U.S. Federal Trade Commission granted early termination of the required 30-day waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended.

The transactions contemplated by the Merger Agreement are expected to close in the second half of 2026, subject to approval by Parent shareholders, the receipt of remaining applicable regulatory approvals and the satisfaction of other customary closing conditions.

Important Information About the Proposed Transaction and Where to Find It

In connection with the proposed transaction, Parent has filed with the Securities and Exchange Commission ("SEC") a registration statement on Form S-4 to register the common stock of Parent to be issued in connection with the proposed transaction. The registration statement includes a document that serves as a proxy statement and prospectus of Parent (the "proxy statement/prospectus"), and Parent will file other documents regarding the proposed transaction with the SEC. This document is not a substitute for the registration statement, the proxy statement/prospectus, or any other document that Parent has filed or may file with the SEC. BEFORE MAKING ANY VOTING DECISION, INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE REGISTRATION STATEMENT, THE PROXY STATEMENT/PROSPECTUS, AND ANY OTHER RELEVANT DOCUMENTS THAT HAVE BEEN OR MAY BE FILED WITH THE SEC, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THOSE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY IF AND WHEN THEY BECOME AVAILABLE BECAUSE THEY DO AND WILL CONTAIN IMPORTANT INFORMATION ABOUT PARENT AND THE COMPANY, THE PROPOSED TRANSACTION, THE RISKS RELATED THERETO, AND RELATED MATTERS.

After the registration statement has been declared effective, a definitive proxy statement will be mailed to the shareholders of Parent (the "Parent Shareholders"). Investors and security holders will be able to obtain free copies of the registration statement and the proxy statement/prospectus, as each may be amended or supplemented from time to time, and other relevant documents filed by Parent with the SEC (if and when they become available) through the website maintained by the SEC at www.sec.gov. Copies of documents filed with the SEC by Parent, including the proxy statement/prospectus, will be available free of charge from Parent's website at helixesg.com under the "Investors" tab.

Participants in the Solicitation

Parent and certain of its directors and executive officers, and the Company and certain of its directors and executive officers, may be deemed to be participants in the solicitation of proxies from the Parent Shareholders with respect to the proposed transaction under the rules of the SEC. Information regarding the names, affiliations and interests of certain of Parent's directors and executive officers in the solicitation may be found by reading Parent's Annual Report on Form 10-K for the fiscal year ended December 31, 2025 filed with the SEC on February 26, 2026, Parent's subsequent Quarterly Reports on Form 10-Q filed with the SEC, Parent's definitive proxy statement for the 2026 annual meeting of shareholders filed with the SEC on April 1, 2026, the proxy statement/prospectus and other relevant materials that have been or may be filed with the SEC in connection with the proposed transaction. Free copies of these documents may be obtained as described in the paragraphs above. Information regarding the persons who may, under the rules of the SEC, be deemed participants in the solicitation of the Parent Shareholders in connection with the proposed transaction, including a description of their direct and indirect interests, by security holdings or otherwise, is included in the proxy statement/prospectus and will also be set forth in other relevant materials when filed with the SEC.