SEACOR Marine Holdings Inc

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of

the Securities Exchange Act of 1934

Filed by the Registrant ☒

Filed by a Party other than the Registrant ☐

Check the appropriate box:

☐ Preliminary Proxy Statement

☐

Confidential, for Use of the Commission Only (as permitted by Rule

14a-6(e)(2))

☒ Definitive Proxy Statement

☐ Definitive Additional Materials

☐ Soliciting Material Pursuant to

§240.14a-12

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

Notice of 2025 Annual Meeting

And

Proxy Statement

April 23, 2025

Dear Stockholder:

You are cordially invited to attend the 2025 Annual Meeting of Stockholders (the “Annual Meeting”) of SEACOR Marine Holdings Inc. (the “Company”) on Tuesday, June 3, 2025, at 9:00 a.m. (EDT). The Annual Meeting will be a completely “virtual meeting,” held via a live audio webcast. Stockholders may access the meeting by visitingwww.proxydocs.com/SMHI and entering the 16-digit control number, located on your proxy card. As the Annual Meeting will begin promptly at 9:00 a.m. (EDT), we encourage you to access the meeting prior to the start time.

All holders of record of the Company’s outstanding Common Stock at the close of business on April 14, 2025, will be entitled to vote at the Annual Meeting. Your virtual attendance at the 2025 Annual Meeting affords you the same rights and opportunities to participate as you would have at anin-person annual meeting, including the ability to vote and submit questions electronically prior to and during the meeting. We believe the virtual Annual Meeting format will enhance stockholder access and encourage participation and communication with our Board of Directors and management.

Directors, officers and other representatives of the Company are expected to be available at the virtual Annual Meeting and they will be pleased to answer any questions you may have.

Whether or not you expect to attend the Annual Meeting and regardless of the number of shares of the Company’s Common Stock you own, you are encouraged to carefully read the enclosed Proxy Statement and the Company’s Annual Report to Stockholders on Form 10-K for the fiscal year ended December 31, 2024 (the “2024 Annual Report”). You may vote your shares over the Internet atwww.proxypush.com/SMHI or via the toll-free telephone number included herein. If you received a paper copy of a proxy or voting instruction card by mail, you may instead submit your proxy or voting instruction card for the Annual Meeting by completing, signing, dating and returning your proxy or voting instruction card in thepre-addressed envelope provided. Submitting a vote before the Annual Meeting will not preclude you from voting your shares at the virtual Annual Meeting should you decide to join the webcast.

We hope that you will be able to attend the virtual Annual Meeting.

Andrew R. Morse

Non-Executive Chairman of the Board

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF

PROXY MATERIALS FOR THE ANNUAL MEETING OF

STOCKHOLDERS TO BE HELD ON JUNE 3, 2025

This Proxy Statement and the 2024 Annual Report are available athttps://ir.seacormarine.com/financial-information/annual-reports-and-proxy-statements

NOTICE OF 2025 ANNUAL

MEETING OF STOCKHOLDERS

To be Held on Tuesday, June 3, 2025, at 9:00 a.m. (EDT)

April 23, 2025

To Our Stockholders:

The 2025 Annual Meeting of Stockholders (the “Annual Meeting”) of SEACOR Marine Holdings Inc. (the “Company”) will be held on Tuesday, June 3, 2025, at 9:00 a.m. (EDT), exclusively online via a live audio webcast atwww.proxydocs.com/SMHI, for the following purposes:

Only holders of record of the Company’s Common Stock at the close of business on April 14, 2025, will be entitled to notice of and to vote at the virtual Annual Meeting. See the “Solicitation of Proxies, Voting and Revocation” section of the accompanying Proxy Statement for the place where the list of stockholders may be examined. The accompanying Proxy Statement is being first sent to stockholders on or about May 7, 2025.

Your vote is very important! Whether or not you plan to attend the virtual Annual Meeting, you are encouraged to read the enclosed Proxy Statement and 2024 Annual Report carefully and submit your proxy or voting instructions promptly so that your shares of the Company’s Common Stock may be represented at the Annual Meeting. You may vote your shares over the Internet atwww.proxypush.com/SMHI, by phoning the toll-free telephone number on the voting instruction card, or by completing, signing, dating and returning the enclosed proxy card. If you attend the virtual Annual Meeting by webcast, you may revoke your proxy and vote your shares electronically at the virtual meeting. See the “Attending the Annual Meeting Virtually” and “Voting and Quorum” sections of the accompanying Proxy Statement for additional instructions and information on voting.

Andrew H. Everett II

Senior Vice President,

General Counsel and Secretary