1
 
   
      AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON MAY 24, 1996
    
 
                                                       REGISTRATION NO. 333-2680
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- --------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
 
                             ---------------------
                                 POST-EFFECTIVE
   
                                AMENDMENT NO. 2
    
                                       TO
                                 FORMS S-4/S-1
 
            REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933
 
                             ---------------------
                        DIAMOND OFFSHORE DRILLING, INC.
             (Exact Name of Registrant as Specified in Its Charter)
 

                                                              
             DELAWARE                            1381                           76-0321760
   (State or Other Jurisdiction      (Primary Standard Industrial            (I.R.S. Employer
of Incorporation or Organization)    Classification Code Number)          Identification Number)

        DIAMOND OFFSHORE DRILLING, INC.                      RICHARD L. LIONBERGER, ESQ.
         15415 KATY FREEWAY, SUITE 400              VICE PRESIDENT, GENERAL COUNSEL AND SECRETARY
             HOUSTON, TEXAS 77094                           15415 KATY FREEWAY, SUITE 400
                (713) 492-5300                                   HOUSTON, TEXAS 77094
  (Address, Including Zip Code, and Telephone                       (713) 492-5300
                     Number,                            (Name, Address, Including Zip Code and
     Including Area Code, of Registrant's                  Telephone Number, Including Area
         Principal Executive Offices)                        Code, of Agent For Service)

 
                                   Copies to:
 

                                            
            JAMES L. RICE III, ESQ.                             MORRIS J. KRAMER, ESQ.
          WEIL, GOTSHAL & MANGES LLP                          ROBERT M. CHILSTROM, ESQ.
           700 LOUISIANA, SUITE 1600                     SKADDEN, ARPS, SLATE, MEAGHER & FLOM
             HOUSTON, TEXAS 77002                                  919 THIRD AVENUE
                (713) 546-5000                                 NEW YORK, NEW YORK 10022
                                                                    (212) 735-3000

 
                             ---------------------
     APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC: As soon as
practicable after this Registration Statement becomes effective and all other
conditions to the amalgamation (the "Acquisition") of AO Acquisition Limited
with Arethusa (Off-Shore) Limited pursuant to the Plan of Acquisition described
in the enclosed Prospectus/Joint Proxy Statement have been satisfied or waived.
If any of the securities being registered on these Forms are to be offered on a
delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or interest
reinvestment plans, check the following box.  /X/
 
                             ---------------------
     THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(A),
MAY DETERMINE.
 
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   2
 
                                EXPLANATORY NOTE
 
   
     This Post-Effective Amendment No. 2 to Registration Statement No. 333-2680
is being filed for the sole purpose of adding the following exhibit to the
Registration Statement: Term Drilling Contract dated March 29, 1996 between
Diamond Offshore and Chevron U.S.A. Production Company with respect to the Ocean
Quest.
    
 
                                      II-1
   3
 
FORM S-4 ITEM 21/FORM S-1 ITEM 16. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES.
 
     (a) Exhibits
 
   


       EXHIBIT
         NO.                                       DESCRIPTION
       -------                                     -----------
                  
           1.1       Form of U.S. Purchase Agreement*
           1.2       Form of International Purchase Agreement*
           2.1       Plan of Acquisition*
           2.2       Amendment No. 1 to Plan of Acquisition*
           2.3       Amalgamation Agreement*
           3.1       Restated Certificate of Incorporation of Diamond Offshore (incorporated
                     by reference herein to Exhibit 3.1 of Diamond Offshore's Annual Report
                     on Form 10-K for the fiscal year ended December 31, 1995)
           3.2       Amended By-laws of Diamond Offshore*
           3.2.1     Amendment of the Company's By-laws on November 8, 1995*
           3.2.2     Amendment of the Company's By-laws on April 3, 1996*
           5.1       Opinion of Weil, Gotshal & Manges LLP regarding validity of the
                     securities being registered*
           8.1       Opinion of Weil, Gotshal & Manges LLP regarding certain tax matters*
          10.1       Fee Agreement*
          10.2       Amendment No. 1 to Fee Agreement*
          10.3       Loews Stockholder's Agreement*
          10.4       Amendment No. 1 to Loews Stockholder's Agreement*
          10.5       Shareholders Agreement*
          10.6       Amendment No. 1 to Shareholders Agreement*
          10.7       Termination and Settlement Agreement dated October 10, 1995 between
                     Loews and Diamond Offshore (incorporated by reference herein to Exhibit
                     10.1 of Diamond Offshore's Annual Report on Form 10-K for the fiscal
                     year ended December 31, 1995)
          10.8       Registration Rights Agreement dated October 16, 1995 between Loews and
                     Diamond Offshore (incorporated by reference herein to Exhibit 10.2 of
                     Diamond Offshore's Annual Report on Form 10-K for the fiscal year ended
                     December 31, 1995)
          10.9       Services Agreement dated October 16, 1995 between Loews and Diamond
                     Offshore (incorporated by reference herein to Exhibit 10.3 of Diamond
                     Offshore's Annual Report on Form 10-K for the fiscal year ended December
                     31, 1995)
          10.10      Agreement ("Rose Employment Agreement"), dated November 1, 1992, between
                     Diamond Offshore and Robert E. Rose (incorporated by reference herein to
                     Exhibit 10.7 of Diamond Offshore's Registration Statement No. 33-95484
                     on Form S-1)
          10.11      Amendment, dated December 27, 1995, to the Rose Employment Agreement
                     (incorporated by reference herein to Exhibit 10.5 of Diamond Offshore's
                     Annual Report on Form 10-K for the fiscal year ended December 31, 1995)
          10.12      Credit Agreement among Diamond Offshore, Diamond Offshore Limited,
                     various lending institutions, Bankers Trust Company and Christiania Bank
                     og Kreditkasse, New York Branch, as Co-Arrangers and Bankers Trust
                     Company, as Administrative Agent dated as of February 8, 1996 and
                     amended and restated as of March 27, 1996*

    
 
                                      II-2
   4
 
   


       EXHIBIT
         NO.                                       DESCRIPTION
       -------                                     -----------
                  
          10.13      Diamond Offshore Management Bonus Program (incorporated by reference
                     herein to Exhibit 10.9 of Diamond Offshore's Registration Statement No.
                     33-95484 on Form S-1)
          10.14      Form of Diamond Offshore Executive Deferred Compensation Plan
                     (incorporated by reference herein to Exhibit 10.10 of Diamond Offshore's
                     Registration Statement No. 33-95484 on Form S-1)
          10.15      Term Drilling Contract dated March 29, 1996 between Diamond Offshore and
                     Chevron U.S.A. Production Company with respect to the Ocean Quest
          10.16      Letter of Intent entered into September 6, 1995 between Diamond Offshore
                     and Texaco Exploration and Production Inc. with respect to the Ocean
                     Star (formerly named Ocean Countess) (incorporated by reference herein
                     to Exhibit 10.12 of Diamond Offshore's Registration Statement No.
                     33-95484 on Form S-1)
          10.17      Diamond Offshore Drilling, Inc. Nonqualified Stock Option Plan for
                     Certain Former Directors of Arethusa*
          10.18      Diamond Offshore Drilling, Inc. Stock Option Plan for Certain Former
                     Employees of Arethusa*
          21.1       List of Subsidiaries of Diamond Offshore*
          23.1       Consent of Deloitte & Touche LLP*
          23.2       Consent of Arthur Andersen & Co.*
          23.3       Consent of Klynveld Peat Marwick Goerdeler*
          23.4       Consent of Weil, Gotshal & Manges LLP. Reference is made to Exhibit 5.1
          23.5       Consent of Weil, Gotshal & Manges LLP. Reference is made to Exhibit 8.1
          23.6       Consent of CS First Boston Corporation*
          23.7       Consent of Merrill Lynch, Pierce, Fenner & Smith Incorporated*
          24.1       Powers of Attorney*
          99.1       Fairness Opinion of CS First Boston Corporation*
          99.2       Fairness Opinion of Merrill Lynch, Pierce, Fenner & Smith Incorporated*
          99.3       Excerpts from The Companies Act of 1981 of Bermuda, as amended*
          99.4       Form of Diamond Offshore proxy card*
          99.5       Form of Arethusa proxy card*

    
 
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*   Previously filed.
 
   
     (b) Financial Statement Schedules
    
 
        Not applicable.
 
                                      II-3
   5
 
                                   SIGNATURES
 
   
     Pursuant to the requirements of the Securities Act of 1933, as amended, the
registrant has duly caused this Post-Effective Amendment No. 2 to Registration
Statement on Forms S-4/S-1 to be signed on its behalf by the undersigned,
thereunto duly authorized, in the City of Houston, State of Texas, on May 24th,
1996.
    
 
                                            DIAMOND OFFSHORE DRILLING, INC.
 
                                            By: /s/  RICHARD L. LIONBERGER
                                                --------------------------------
                                            Name: Richard L. Lionberger
                                            Title:  Vice President, General
                                            Counsel and Secretary
 
   
     Pursuant to the requirements of the Securities Act of 1933, as amended,
this Post-Effective Amendment No. 2 to Registration Statement has been signed by
the following persons in the capacities and on the dates indicated.
    
 
   


                  SIGNATURE                               TITLE                     DATE
- ---------------------------------------------  ----------------------------   -----------------
                                                                        
           /s/  ROBERT E. ROSE*                President, Chief Executive          May 24, 1996
  --------------------------------------         Officer and Director
                Robert E. Rose                   (principal executive
                                                 officer)

       /s/  LAWRENCE R. DICKERSON*             Senior Vice President and           May 24, 1996
  --------------------------------------         Chief Financial Officer
            Lawrence R. Dickerson                (principal financial
                                                 officer)

             /s/  GARY T. KRENEK*              Controller (principal               May 24, 1996
  --------------------------------------         accounting officer)
                  Gary T. Krenek

             /s/  JAMES S. TISCH*              Chairman of the Board               May 24, 1996
  --------------------------------------
                  James S. Tisch

           /s/  HERBERT C. HOFMANN*            Director                            May 24, 1996
  --------------------------------------
                Herbert C. Hofmann

      *By: /s/ RICHARD L. LIONBERGER
  --------------------------------------
            Richard L. Lionberger
              Attorney-in-Fact

    
 
                                      II-4
   6
 
                               INDEX TO EXHIBITS
 
   


    EXHIBIT
      NO.                                    DESCRIPTION
    -------                                  ------------
                                                                           
       1.1      Form of U.S. Purchase Agreement*
       1.2      Form of International Purchase Agreement*
       2.1      Plan of Acquisition*
       2.2      Amendment No. 1 to Plan of Acquisition*
       2.3      Amalgamation Agreement*
       3.1      Restated Certificate of Incorporation of Diamond Offshore
                (incorporated by reference herein to Exhibit 3.1 of Diamond Offshore's
                Annual Report on Form 10-K for the fiscal year ended December 31,
                1995)
       3.2      Amended By-laws of Diamond Offshore*
       3.2.1    Amendment of the Company's By-laws on November 8, 1995*
       3.2.2    Amendment of the Company's By-laws on April 3, 1996*
       5.1      Opinion of Weil, Gotshal & Manges LLP regarding validity of the
                securities being registered*
       8.1      Opinion of Weil, Gotshal & Manges LLP regarding certain tax matters*
      10.1      Fee Agreement*
      10.2      Amendment No. 1 to Fee Agreement*
      10.3      Loews Stockholder's Agreement*
      10.4      Amendment No. 1 to Loews Stockholder's Agreement*
      10.5      Shareholders Agreement*
      10.6      Amendment No. 1 to Shareholders Agreement*
      10.7      Termination and Settlement Agreement dated October 10, 1995 between
                Loews and Diamond Offshore (incorporated by reference herein to
                Exhibit 10.1 of Diamond Offshore's Annual Report on Form 10-K for the
                fiscal year ended December 31, 1995)
      10.8      Registration Rights Agreement dated October 16, 1995 between Loews and
                Diamond Offshore (incorporated by reference herein to Exhibit 10.2 of
                Diamond Offshore's Annual Report on Form 10-K for the fiscal year
                ended December 31, 1995)
      10.9      Services Agreement dated October 16, 1995 between Loews and Diamond
                Offshore (incorporated by reference herein to Exhibit 10.3 of Diamond
                Offshore's Annual Report on Form 10-K for the fiscal year ended
                December 31, 1995)
      10.10     Agreement ("Rose Employment Agreement"), dated November 1, 1992,
                between Diamond Offshore and Robert E. Rose (incorporated by reference
                herein to Exhibit 10.7 of Diamond Offshore's Registration Statement
                No. 33-95484 on Form S-1)
      10.11     Amendment, dated December 27, 1995, to the Rose Employment Agreement
                (incorporated by reference herein to Exhibit 10.5 of Diamond
                Offshore's Annual Report on Form 10-K for the fiscal year ended
                December 31, 1995)
      10.12     Credit Agreement among Diamond Offshore, Diamond Offshore Limited,
                various lending institutions, Bankers Trust Company and Christiania
                Bank og Kreditkasse, New York Branch, as Co-Arrangers and Bankers
                Trust Company, as Administrative Agent dated as of February 8, 1996
                and amended and restated as of March 27, 1996*

    
   7
 
   


    EXHIBIT
      NO.                                    DESCRIPTION
    -------                                  -----------
                                                                           
      10.13     Diamond Offshore Management Bonus Program (incorporated by reference
                herein to Exhibit 10.9 of Diamond Offshore's Registration Statement
                No. 33-95484 on Form S-1)
      10.14     Form of Diamond Offshore Executive Deferred Compensation Plan
                (incorporated by reference herein to Exhibit 10.10 of Diamond
                Offshore's Registration Statement No. 33-95484 on Form S-1)
      10.15     Term Drilling Contract dated March 29, 1996 between Diamond Offshore
                and Chevron U.S.A. Production Company with respect to the Ocean Quest
      10.16     Letter of Intent entered into September 6, 1995 between Diamond
                Offshore and Texaco Exploration and Production Inc. with respect to
                the Ocean Star (formerly named Ocean Countess) (incorporated by
                reference herein to Exhibit 10.12 of Diamond Offshore's Registration
                Statement No. 33-95484 on Form S-1)
      10.17     Diamond Offshore Drilling, Inc. Nonqualified Stock Option Plan for
                Certain Former Directors of Arethusa*
      10.18     Diamond Offshore Drilling, Inc. Stock Option Plan for Certain Former
                Employees of Arethusa*
      21.1      List of Subsidiaries of Diamond Offshore*
      23.1      Consent of Deloitte & Touche LLP*
      23.2      Consent of Arthur Andersen & Co.*
      23.3      Consent of Klynveld Peat Marwick Goerdeler*
      23.4      Consent of Weil, Gotshal & Manges LLP. Reference is made to Exhibit
                5.1
      23.5      Consent of Weil, Gotshal & Manges LLP. Reference is made to Exhibit
                8.1
      23.6      Consent of CS First Boston Corporation*
      23.7      Consent of Merrill Lynch, Pierce, Fenner & Smith Incorporated*
      24.1      Powers of Attorney*
      99.1      Fairness Opinion of CS First Boston Corporation*
      99.2      Fairness Opinion of Merrill Lynch, Pierce, Fenner & Smith
                Incorporated*
      99.3      Excerpts from The Companies Act of 1981 of Bermuda, as amended*
      99.4      Form of Diamond Offshore proxy card*
      99.5      Form of Arethusa proxy card*

    
 
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*   Previously filed.