EXHIBIT 5.1
                                                                     -----------

                           WEIL, GOTSHAL & MANGES LLP           Austin
                                767 Fifth Avenue                Boston
                               New York, NY 10153               Brussels
                                 (212) 310-8000                 Budapest
                              Fax: (212) 310-8007               Dallas
                                                                Frankfurt
                                                                Houston
                                                                London
                                                                Miami
                                                                Munich
                                                                Paris
                                                                Prague
                                 March 12, 2007                 Shanghai
                                                                Silicon Valley
                                                                Singapore
                                                                Warsaw
                                                                Washington, D.C.
SEACOR Holdings Inc.
2200 Eller Drive, P.O. Box 13038
Fort Lauderdale, Florida 33316


Ladies and Gentlemen:

            We have acted as counsel to SEACOR Holdings Inc., a Delaware
corporation (the "Company"), in connection with the preparation and filing with
the Securities and Exchange Commission (the "Commission") of the Company's
Registration Statement on Form S-3 (the "Registration Statement"), under the
Securities Act of 1933, as amended (the "Securities Act"), relating to the
issuance and/or sale from time to time of an indeterminate number of shares of
the Company's common stock, par value $0.01 per share (the "Shares").

            The Shares being registered under the Registration Statement may be
offered on a continued or delayed basis pursuant to the provisions of Rule 415
of the Securities Act by the Company or by selling securityholders.

            In so acting, we have examined originals or copies (certified or
otherwise identified to our satisfaction) of (i) the Restated Certificate of
Incorporation of the Company, as amended, (ii) the Registration Statement, (iii)
the prospectus contained in the Registration Statement (the "Prospectus"), and
(iv) such corporate records, agreements, documents and other instruments, and
such certificates or comparable documents of public officials and of officers
and representatives of the Company, and have made such inquiries of such
officers and representatives, as we have deemed relevant and necessary as a
basis for the opinions hereinafter set forth.

            In such examination, we have assumed the genuineness of all
signatures, the legal capacity of all natural persons, the authenticity of all
documents submitted to us as originals, the conformity to original documents of
all documents submitted to us as certified, conformed or photostatic copies and
the authenticity of the originals of such latter documents. As to all questions
of fact material to these opinions that have not been independently established,




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March 12, 2007
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we have relied upon certificates or comparable documents of officers and
representatives of the Company.

            Based upon and subject to the foregoing and assuming that (A) the
Registration Statement and any amendments thereto (including any post-effective
amendments) will have become effective and comply with all applicable laws and
no stop order suspending the Registration Statement's effectiveness will have
been issued and remain in effect, in each case, at the time the Shares are
offered or issued as contemplated by the Registration Statement, (B) a
prospectus supplement will have been prepared and filed with the Commission
describing the Shares offered thereby and will at all relevant times comply with
all applicable laws, (C) the Company has timely filed all necessary reports
pursuant to the Securities Exchange Act of 1934, as amended, which are
incorporated into the Registration Statement by reference, (D) all Shares will
be issued and sold in compliance with applicable federal and state securities
laws and in the manner stated in the Registration Statement and the appropriate
prospectus supplement, (E) a definitive purchase, underwriting or similar
agreement and any other necessary agreement with respect to any Shares will have
been duly authorized and validly executed and delivered by the Company and the
other party or parties thereto and the Shares to be issued thereby will have
been duly authorized by all necessary corporate action on the part of the
Company and (F) the Company has received the consideration specified in any
applicable underwriting, purchase or other agreement approved by the Company's
board of directors, we are of the opinion that the Shares will be validly
issued, fully paid and nonassessable.

            The opinion expressed herein is limited to the corporate laws of the
State of Delaware, and we express no opinion as to the effect on the matters
covered by this letter of the laws of any other jurisdiction.

            We hereby consent to the use of this letter as an exhibit to the
Registration Statement and to any and all references to our firm in the
Prospectus which is a part of the Registration Statement.

                                    Very truly yours,


                                   /s/  Weil, Gotshal & Manges LLP