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EXHIBIT 10a

AMENDMENT NO. 1
TO
CREDIT AGREEMENT

THIS AMENDMENT NO. 1, dated as of March 28, 2005 (“Amendment No. 1”), to the
CREDIT AGREEMENT, dated as of May 28, 2003 is made by and among ROWAN COMPANIES,
INC., a Delaware corporation (the “Shipowner”), GOVCO INCORPORATED, a Delaware
corporation (the “Primary Lender”), CITIBANK, N.A., a national banking
association (the “Alternate Lender”), CITIBANK, N.A., a national banking
association, as facility agent for both the Primary Lender and the Alternate
Lender (and their respective successors and assigns) with respect to the
Floating Rate Note, and its permitted successors and assigns (in such capacity,
the “Facility Agent”), and CITICORP NORTH AMERICA, INC., a Delaware corporation,
as administrative agent for the Primary Lender and the commercial paper holders
of the Primary Lender (and their respective successors and assigns) (in such
capacity, together with its permitted successors and assigns, the
“Administrative Agent,” and together with the Facility Agent, the “Agents”)
(collectively the “Parties”).

WHEREAS, to aid in the construction of the self-elevating mobile offshore
drilling unit to be named “TARZAN II” (the “Vessel”), on May 28, 2003, the
Parties executed the Credit Agreement, providing for the delivery of no more
than $89,658,000 principal amount of notes designated "United States Government
Guaranteed Ship Financing Obligations, TARZAN II Series";

WHEREAS, the projected Delivery Date of the Vessel, which was April 1, 2005,
has, for a variety of reasons, been postponed to September 2005;

WHEREAS, in connection with the postponement of the projected Delivery Date of
the Vessel, the Parties wish to amend the Credit Agreement in order to extend
the Final Disbursement Date and Commitment Termination Date thereunder from
April 1, 2005 to December 31, 2005;

NOW THEREFORE, in consideration of the mutual rights and obligations set forth
herein and of other good and valuable consideration, the receipt and sufficiency
of which are hereby acknowledged, the Parties agree as follows:

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1. Section 2.02. Section 2.02 of the Credit Agreement is hereby amended to read
as follows:

2.02 Availability. Disbursements under the Credit Facility may be made once a
calendar month and up to and including the Final Disbursement Date. “Final
Disbursement Date” shall mean the earliest of (x) December 31, 2005, (y) upon
the request of the Secretary, the date upon which the Trigger Event (as defined
in Section 2.05) shall occur, or (z) the date on which the Available Amount
under the Credit Facility is canceled in accordance with Section 9.01 or reduced
to zero.

2. Concerning Exhibit 1. (a) The following definition in Exhibit 1 to the Credit
Agreement is hereby amended to read as follows:

“Commitment Termination Date” means December 31, 2005, as such date may be
extended from time to time pursuant to Section 2.06(a).

(b) Exhibit 1 to the Credit Agreement is further amended by adding the following
definition to read as follows:
 
“Amendment No. 1 to the Credit Agreement” means the Amendment No. 1 to the
Credit Agreement dated March 28, 2005, among the Shipowner, the Lenders and
Agents.

3. All other capitalized terms used herein have the meanings set forth in
Exhibit 1 to the Credit Agreement.

4. Except as so amended, the provisions of the Credit Agreement are hereby
confirmed, and shall remain in full force and effect.

5. This Amendment No. 1 to the Credit Agreement may be executed in several
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

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IN WITNESS WHEREOF, this Amendment No. 1 to the Credit Agreement has been duly
executed by the Parties as of the day and year first above written.

ROWAN COMPANIES, INC., as 
the Shipowner
 
GOVCO INCORPORATED, as the Primary Lender, by Citicorp North America, Inc., its
attorney-in-fact.
     
By: ______________________________
 
By: _______________________________
(Signature)
 
(Signature)
     
Name: E. E. Thiele .
 
Name: P. A. Botticelli .
(Print)
 
(Print)
     
Title: Senior Vice President .
 
Title: Vice President .
(Print)
 
(Print)
     

CITIBANK, N.A., as Facility Agent
 
CITIBANK, N.A., as the Alternate Lender
     
By: ______________________________
 
By: _______________________________
(Signature)
 
(Signature)
     
Name: P. A. Botticelli .
 
Name: P. A. Botticelli .
(Print)
 
(Print)
     
Title: Vice President .
 
Title: Vice President .
(Print)
 
(Print)

   
CITICORP NORTH AMERICA, INC., as the Administrative Agent
         
By: _______________________________
   
(Signature)
         
Name: P. A. Botticelli .
   
(Print)
         
Title: Vice President .
   
(Print)

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CONSENT:

Pursuant to the Section 11.08 of the Credit Agreement, the Secretary hereby
consents to this Amendment No. 1 to the Credit Agreement and confirms the
continued Guarantee of the Obligation of the United States of America pursuant
to Title XI of the Merchant Marine Act, 1936, as amended.

ATTEST:                   UNITED STATES OF AMERICA,
  SECRETARY OF TRANSPORTATION

BY: ___________________________         MARITIME ADMINISTRATION

  By: __________________________________
        Secretary

 
 
 
 
 
 
 
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