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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  SCHEDULE 13G


                   Under the Securities Exchange Act of 1934
                               (Amendment No. )*


                              SEACOR HOLDINGS INC.
                                (Name of Issuer)


                                  COMMON STOCK
                         (Title of Class of Securities)


                                   811904101
                                 (CUSIP Number)


                                 APRIL 4, 2007
            (Date of Event Which Requires Filing of This Statement)


Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

[_]  Rule 13d-1(b)
[X]  Rule 13d-1(c)
[_]  Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities,
and for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section of
the Act but shall be subject to all other provisions of the Act (however, see
the Notes).

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CUSIP No. 811904101               SCHEDULE 13G                    Page 2 of 8
-----------------------                                  ----------------------

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1       Name of Reporting Person:

        KENSICO CAPITAL MANAGEMENT CORPORATION

        I.R.S. Identification Nos. of Above Persons (entities only)

        13-4079277
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2       Check the Appropriate Box if a Member of a Group:
                                                                (a)   [_]
                                                                (b)   [_]
--------------------------------------------------------------------------------
3       SEC Use Only


--------------------------------------------------------------------------------
4       Citizenship or Place of Organization:

        Delaware
--------------------------------------------------------------------------------
                                     5       Sole Voting Power
             Number of
                                             1,277,640
               Shares                -------------------------------------------
                                     6       Shared Voting Power
            Beneficially
                                             -0-
             Owned by                -------------------------------------------
                                     7       Sole Dispositive Power
               Each
                                             1,277,640
          Reporting Person           -------------------------------------------
                                     8       Shared Dispositive Power
               With
                                             -0-
--------------------------------------------------------------------------------
9       Aggregate Amount Beneficially Owned by Each Reporting Person:

        1,277,640
--------------------------------------------------------------------------------
10      Check Box If the Aggregate Amount in Row (9) Excludes
        Certain Shares:
                                                                      [_]
--------------------------------------------------------------------------------
11      Percent of Class Represented by Amount in Row (9):

        5.21%
--------------------------------------------------------------------------------
12      Type of Reporting Person:

        CO
--------------------------------------------------------------------------------


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CUSIP No. 811904101               SCHEDULE 13G                    Page 3 of 8
-----------------------                                  ----------------------

--------------------------------------------------------------------------------
1       Name of Reporting Person:

        MICHAEL LOWENSTEIN

        I.R.S. Identification Nos. of Above Persons (entities only)

--------------------------------------------------------------------------------
2       Check the Appropriate Box if a Member of a Group:
                                                                (a)   [_]
                                                                (b)   [_]
--------------------------------------------------------------------------------
3       SEC Use Only

--------------------------------------------------------------------------------
4       Citizenship or Place of Organization:

        United States of America
--------------------------------------------------------------------------------
                                     5       Sole Voting Power
             Number of
                                             1,277,640
               Shares                -------------------------------------------
                                     6       Shared Voting Power
            Beneficially
                                             -0-
             Owned by                -------------------------------------------
                                     7       Sole Dispositive Power
               Each
                                             1,277,640
          Reporting Person           -------------------------------------------
                                     8       Shared Dispositive Power
               With
                                             -0-
--------------------------------------------------------------------------------
9       Aggregate Amount Beneficially Owned by Each Reporting Person:

        1,277,640
--------------------------------------------------------------------------------
10      Check Box If the Aggregate Amount in Row (9) Excludes
        Certain Shares:
                                                                      [_]
--------------------------------------------------------------------------------
11      Percent of Class Represented by Amount in Row (9):

        5.21%
--------------------------------------------------------------------------------
12      Type of Reporting Person:

        IN; HC
--------------------------------------------------------------------------------


-----------------------                                  ----------------------
CUSIP No. 811904101               SCHEDULE 13G                    Page 4 of 8
-----------------------                                  ----------------------

--------------------------------------------------------------------------------
1       Name of Reporting Person:

        THOMAS J. COLEMAN

        I.R.S. Identification Nos. of Above Persons (entities only)

--------------------------------------------------------------------------------
2       Check the Appropriate Box if a Member of a Group:
                                                                (a)   [_]
                                                                (b)   [_]
--------------------------------------------------------------------------------
3       SEC Use Only

--------------------------------------------------------------------------------
4       Citizenship or Place of Organization:

        United States of America
--------------------------------------------------------------------------------
                                     5       Sole Voting Power
             Number of
                                             1,277,640
               Shares                -------------------------------------------
                                     6       Shared Voting Power
            Beneficially
                                             -0-
             Owned by                -------------------------------------------
                                     7       Sole Dispositive Power
               Each
                                             1,277,640
          Reporting Person           -------------------------------------------
                                     8       Shared Dispositive Power
               With
                                             -0-
--------------------------------------------------------------------------------
9       Aggregate Amount Beneficially Owned by Each Reporting Person:

        1,277,640
--------------------------------------------------------------------------------
10      Check Box If the Aggregate Amount in Row (9) Excludes
        Certain Shares:
                                                                      [_]
--------------------------------------------------------------------------------
11      Percent of Class Represented by Amount in Row (9):

        5.21%
--------------------------------------------------------------------------------
12      Type of Reporting Person:

        IN; HC
--------------------------------------------------------------------------------


-----------------------                                  ----------------------
CUSIP No. 811904101               SCHEDULE 13G                    Page 5 of 8
-----------------------                                  ----------------------


Item 1(a).        Name of Issuer:

                  Seacor Holdings Inc. (the "Company")

Item 1(b).        Address of Issuer's Principal Executive Offices:

                  2200 Eller Drive
                  P.O. Box 13038
                  Fort Lauderdale, FL 33316, United States


Item 2(a).        Name of Persons Filing:

                  The  Statement  is filed on behalf  of each of the  following
                  persons (collectively, the "Reporting Persons"):

                  (i)   Kensico Capital  Management  Company  ("Kensico Capital
                        Management");

                  (ii)  Michael Lowenstein ("Mr. Lowenstein"); and

                  (iii) Thomas J. Coleman ("Mr. Coleman").

                  This  statement  relates  to shares  of  Common  Stock of the
                  Company  held for the accounts of Kensico  Partners,  L.P., a
                  Delaware limited partnership  ("Kensico  Partners"),  Kensico
                  Associates,  L.P., a Delaware limited  partnership  ("Kensico
                  Associates"),  and Kensico  Offshore  Fund,  Ltd.,  a limited
                  liability  company  organized  under  the laws of the  Cayman
                  Islands,   B.W.I.  ("Kensico  Offshore"  and,  together  with
                  Kensico  Partners  and  Kensico  Associates,   the  "Funds").
                  Kensico Capital  Management  serves as investment  manager to
                  the Funds and, in such capacity, may be deemed to have voting
                  and  dispositive  power over the shares held for the accounts
                  of  the  Funds.  Kensico  Capital  LLC,  a  Delaware  limited
                  liability  company  ("Kensico  Capital"),  serves as  General
                  Partner  of the  Funds,  other  than  Kensico  Offshore.  Mr.
                  Lowenstein and Mr. Coleman serve as  Co-Presidents of Kensico
                  Capital  Management  and  are  Managing  Members  of  Kensico
                  Capital.

Item 2(b).        Address of Principal Business Office:

                  For each Reporting Person:

                  Michael Lowenstein
                  Kensico Capital Management Corporation
                  55 Railroad Avenue, 2nd Floor
                  Greenwich, Connecticut 06830

Item 2(c).        Citizenship:

                  See row 4 of each Reporting Persons' cover page.


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CUSIP No. 811904101               SCHEDULE 13G                    Page 6 of 8
-----------------------                                  ----------------------


Item 2(d).        Title of Class of Securities: Common Stock

Item 2(e).        CUSIP Number: 811904101

Item 3.           Not applicable.

Item 4.           Ownership.

                  For each Reporting Person:

                  (a)   Amount beneficially owned:

                  As of December 31, 2006, each of Kensico Capital  Management,
                  Mr.  Lowenstein  and  Mr.  Coleman  may be  deemed  to be the
                  beneficial owner of the 1,277,640 shares of Common Stock held
                  for  the  accounts  of  the  Funds.   Kensico  Partners  owns
                  beneficially   310,400   shares  of  Common  Stock,   Kensico
                  Associates owns  beneficially  420,840 shares of Common Stock
                  and Kensico  Offshore  owns  beneficially  546,400  shares of
                  Common Stock.

                  (b)   Percent of class:

                        5.21% of the total outstanding  shares of Common Stock,
                        from which Kensico  Partners,  Kensico  Associates  and
                        Kensico   Offshore   own   1.26%,   1.72%  and   2.23%,
                        respectively.  This percentage is based upon 24,531,005
                        shares of Common  Stock  issued  and  outstanding  (the
                        number  of  shares  of  Common  Stock  reported  in the
                        Company's Form 10-K filed March 1, 2007).

                  (c)   Number of shares to which each Reporting Person has:

                        (i)   Sole power to vote or direct the vote: 1,277,640

                        (ii)  Shared power to vote or direct the vote: -0-

                        (iii) Sole   power  to   dispose   or  to  direct   the
                              disposition of: 1,277,640

                        (iv)  Shared   power  to   dispose  of  or  direct  the
                              disposition of: -0-

Item 5.           Ownership of Five Percent or Less of a Class.

                  Not Applicable.

Item 6.           Ownership of More than Five Percent on Behalf of Another
                  Person.

                  (i)   The  partners  of  Kensico  Partners  have the right to
                  participate  in the receipt of  dividends  from,  or proceeds
                  from the sale of, the  shares  held by  Kensico  Partners  in
                  accordance  with  their  partnership   interests  in  Kensico
                  Partners.


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CUSIP No. 811904101               SCHEDULE 13G                    Page 7 of 8
-----------------------                                  ----------------------


                  (ii)  The  partners of Kensico  Associates  have the right to
                  participate  in the receipt of  dividends  from,  or proceeds
                  from the sale of, the shares  held by Kensico  Associates  in
                  accordance with the partnership of Kensico Associates.

                  (iii) The  shareholders of Kensico Offshore have the right to
                  participate  in the receipt of  dividends  from,  or proceeds
                  from the sale of, the  shares  held by  Kensico  Offshore  in
                  accordance   with  their   ownership   interests  of  Kensico
                  Offshore.

Item 7.           Identification and Classification of the Subsidiary Which
                  Acquired the Security Being Reported By the Parent Holding
                  Company.

                  Not Applicable.

Item 8.           Identification and Classification of Members of the Group.

                  Not Applicable.

Item 9.           Notice of Dissolution of a Group.

                  Not Applicable.

Item 10.          Certification.

                  By signing below I certify that, to the best of my knowledge
                  and belief, the securities referred to above were not
                  acquired and are not held for the purpose of or with the
                  effect of changing or influencing the control of the issuer
                  of the securities and were not acquired and are not held in
                  connection with or as a participant in any transaction having
                  that purpose or effect.



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CUSIP No. 811904101               SCHEDULE 13G                    Page 8 of 8
-----------------------                                  ----------------------


                                   SIGNATURE

         After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true,  complete and
correct.

Dated:   April 20, 2007


                                  KENSICO CAPITAL MANAGEMENT CORPORATION


                                  BY:     /s/ Michael Lowenstein
                                  ----------------------------------------
                                                  Signature


                                  Michael Lowenstein, Authorized Signatory
                                  ----------------------------------------
                                                  Name/Title



                                  MICHAEL LOWENSTEIN


                                          /s/ Michael Lowenstein
                                  ----------------------------------------
                                                  Signature



                                  THOMAS J. COLEMAN


                                           /s/ Thomas J. Coleman
                                  ----------------------------------------
                                                  Signature