EXHIBIT 4.24

                GUARANTY AGREEMENT IN FAVOR OF THE UNITED STATES

      This Guaranty Agreement (the "Guaranty Agreement") is dated this 9th day
April, 1999 by PETRODRILL FIVE LIMITED, a British Virgin Islands international
business company (the "Guarantor"), to the United States of America, represented
by the Secretary of Transportation, acting by and through the Maritime
Administrator (the "Secretary").

      RECITALS:

      A. WHEREAS, the Guarantor is the sister company of PETRODRILL FOUR
LIMITED, (the "Shipowner"); and

      B. WHEREAS, the Shipowner, in connection with the financing of the cost of
construction of the AMETHYST 4, to be wholly owned by the Shipowner (the
"Vessels"), on the date hereof, borrowed certain funds and created and
authorized the issuance of obligations designated "United States Government
Guaranteed Export Ship Financing Obligations, AMETHYST 4 Series" (the
"Obligations"), consisting on the date hereof of $149,625,000 aggregate
principal amount of the Obligations, bearing interest at the rate specified
therein and issued under a trust indenture between the Shipowner and FMB Trust
Company, National Association, a national trust company as trustee, dated as of
the date hereof, said Obligations constituting the legal, valid and binding
obligations of the Shipowner; and

      C. WHEREAS, the Shipowner, on the date hereof, accepted the Secretary's
Commitment to Guarantee Obligations (the "Commitment") pursuant to Title XI of
the Merchant Marine Act, 1936, as amended (the "Act"), whereby the Secretary
authorized a guarantee to be endorsed upon each of the Obligations (the
"Guarantees"); and

      D. WHEREAS, the Shipowner has, in consideration of the issuance of the
Guarantees by the Secretary of the payment of the unpaid interest on, and the
unpaid balance of the principal of the Obligations, executed a security
agreement dated the date hereof, between the Shipowner and the Secretary (the
"Security Agreement") and issued and delivered to the Secretary a promissory
note in the principal amount of $149,625,000, (said promissory note, as
originally executed and as the same may hereafter be amended, modified,
supplemented or endorsed, herein called the "Secretary's Note").

      E. WHEREAS, the Secretary has required this Guaranty Agreement from the
Guarantor as an integral part of the consideration offered by or on behalf of
the Shipowner as a condition of the Secretary's decision to enter into the
Commitment to issue the Guarantees, and the Guarantor has agreed to enter into
this Guaranty Agreement for the purpose of guaranteeing the Shipowner's
obligations to the Secretary under the Secretary's Note.


      NOW THEREFORE, in consideration of the premises, and of other good and
valuable consideration, the receipt and adequacy of which is hereby
acknowledged, the Guarantor hereby agrees as follows:

      1. DEFINITIONS. Unless otherwise specifically defined herein, the
capitalized terms used herein which are defined in Schedule X to the Security
Agreement, dated the date hereof and any reference therein to other instruments
shall have the respective meanings stated in Schedule X of the Security
Agreement or such other instruments.

      2.    GUARANTEE.

            a) The Guarantor hereby absolutely, irrevocably and unconditionally
guarantees the due and punctual payment of the principal of and the interest on
the Secretary's Note. The Guarantor shall be required to make said payments
under this Guaranty Agreement upon receipt of a written notice from the
Secretary which states that the Shipowner has not promptly, completely or
effectively made said payments. The failure of Guarantor to receive such a
written notice or the failure of the Secretary to send said notice shall not
relieve the Guarantor of its obligations under this Guaranty Agreement. The
Guarantor shall immediately pay to the Secretary or its designee in immediately
available funds such payments guaranteed herein.

            b) The Guarantor hereby consents and agrees that its obligations
under this Guaranty Agreement will not be discharged by any act or omission to
act of any kind by the Secretary or any other person or any other circumstances
whatsoever (including, but not limited to, any extension, rearrangement or
renewal with respect to any indebtedness or other obligation of the Shipowner
with or without notice to the Guarantor, any waiver of any right of the
Secretary under the terms of the Secretary's Note, the Security Agreement, the
Mortgage or this Guaranty Agreement, any release of security, any transfer or
assignment of rights or obligations accruing to the Secretary under the
Secretary's Note, the Security Agreement, the Mortgage or this Guaranty
Agreement, any corporate reorganization, dissolution, merger, acquisition of or
by or other alteration of the corporate existence or structure of the Shipowner
or the Guarantor, discharge of the Shipowner in bankruptcy, the invalidity,
illegality or unenforceability of the Secretary's Note, the Security Agreement,
the Mortgage or this Guaranty Agreement or the absence of any action to enforce
the obligations of the Shipowner) which might constitute a legal or equitable
discharge of the Guarantor; it being the intention of the Guarantor that this
Guaranty Agreement be absolute, continuing and unconditional and the guarantee
hereunder shall only be discharged by the payment in full of all sums so
guaranteed hereunder.

            c) The Guarantor hereby irrevocably and unconditionally waives: (i)
notice of any of the matters referred to in this Guaranty Agreement and any
action by the Secretary in reliance thereon; (ii) all notices which may be
required by statute, rule of law or otherwise to preserve any rights against the
Guarantor hereunder, including without limitations, any demand, protest, proof
of notice of non-payment of all sums payable under the Secretary's Note or any
notice of any failure on the part of the Shipowner to perform or comply with any
covenant, term or obligations of any agreement to which it is a party; (iii) any
requirement for the enforcement, assertion or exercise of

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any right, remedy, power or privilege under or with respect to the Mortgage, the
Security Agreement or the Secretary's Note; (iv) any requirement of diligence;
(v) any requirement that the Shipowner be joined as a party to any proceedings
for the enforcement of any provision of this Guaranty Agreement or that the
Secretary proceed against any other guarantor executing this Guaranty Agreement
or any other guaranty agreement; (vi) any and all defenses to payment hereunder,
except the defense of payment already made, and agree to confess without
contesting liability hereunder for any judgment entered hereon; (vii)
presentment, demand, protest, notice of protest and dishonor, notice of intent
to accelerate and notice of acceptance; or (viii) the right to require the
Secretary to pursue any remedy in the Secretary's power whatsoever.

            d) The Guarantor hereby agrees that this Guaranty Agreement shall
continue to be effective or shall be reinstated, as the case may be, if at any
time payment of any sum hereby guaranteed is rescinded or must be otherwise
restored or returned by the Secretary, upon the insolvency, bankruptcy or
reorganization of the Shipowner, or otherwise, all as though such payment had
not been made. The Guarantor further agrees that if the maturity of any
obligations guaranteed herein be accelerated by bankruptcy or otherwise, such
maturity shall also be deemed accelerated for the purpose of this Guaranty
Agreement without demand or notice to the Guarantor.

            e) Any amount payable hereunder shall not be subject to any
reduction by reason of any counterclaim, set-off, deduction, abatement or
otherwise.

            f) The Guarantor shall pay all reasonable costs and expenses
(including, without limitation, attorneys' fees and expenses) incurred in
connection with the enforcement of the obligations of the Guarantor under this
Guaranty Agreement.

            g) The Secretary's Note may be amended, modified or endorsed without
the consent of the Guarantor.

            h) The Secretary may enforce the Guarantor's obligations hereunder
without in any way first pursuing or exhausting any other rights or remedies
which the Secretary may have against the Shipowner or any other person, firm or
corporation or against any security the Secretary may hold.

            (i) The Guarantor hereby agrees that this Guaranty Agreement shall
be secured by a mortgage on the AMETHYST 5 upon its delivery.

      3. SECRETARY'S RIGHTS. The Guarantor authorizes the Secretary, without
notice or demand and without affecting the Guarantor's liability hereunder, to
take and hold security for the payment of this Guaranty Agreement and/or any of
the obligations guaranteed herein and exchange, enforce, waive and release any
such security; and to apply such security and direct the order or manner of sale
thereof as the Secretary in his discretion may determine; and to obtain a
guarantee of any of the obligations guaranteed herein from any one or more
persons, corporations or entities whomsoever and at any time or times to
enforce, waive, rearrange, modify, limit or release such other persons,
corporations or entities from their obligations under such guarantees.

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      4. PRIMARY LIABILITY. It is expressly agreed that the liability of the
Guarantor for the payment of the obligations guaranteed herein shall be primary
and not secondary.

      5. REPRESENTATIONS AND WARRANTIES. The Guarantor represents and warrants
as follows:

            a) The Guarantor is a corporation duly organized, validly existing
and in good standing under the laws of the British Virgin Islands, and has full
power and authority (corporate, legal and other) to execute, deliver and carry
out the terms of this Guaranty Agreement;

            b) This Guaranty Agreement has been duly authorized, executed and
delivered by the Guarantor and constitutes the legal, valid and binding
obligation of the Guarantor enforceable against the Guarantor in accordance with
its terms;

            c) The execution, delivery and performance the Guarantor of this
Guaranty Agreement does not require the approval or consent of its shareholders
or of any governmental authority and does not contravene the Guarantor's
Memorandum of Association and Articles of Association or any mortgage, indenture
or other agreement binding upon it, or any law, regulation, order, judgment or
decree applicable to the Guarantor; and

            d) The Guarantor's guarantee pursuant to this Guaranty Agreement may
be expected to benefit, directly or indirectly, the Guarantor.

            e) The Guarantor has fully adequate financial resources, funds, and
assets to satisfy its obligations under this Guaranty Agreement, and the
Guarantor will in the future retain financial resources, funds, and assets to
fully satisfy its obligations under this Guaranty Agreement.

      6. CONTINUING GUARANTEE. This Guaranty Agreement is a continuing guarantee
of payment and collectibility and shall:

            a) Remain in full  force and  effect so long as any  obligation
of the Shipowner to the Secretary referred to herein exists;

            b) Be binding upon the Guarantor, its successors and assigns; and

            c) Be executed and issued for the sole and exclusive benefit of the
United States, and no other party shall be permitted to claim any benefit,
direct or indirect, therefrom. This Guaranty Agreement is nonassignable, any
assignment thereof shall be null and void and have no legal effect whatsoever.

            d) Inure to the benefit of, and be enforceable by the Secretary, his
successors and assigns.

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      7. DEFAULT. A default under the terms of this Guaranty Agreement shall be
deemed to occur if the Guarantor fails to make any payments guaranteed
hereunder.

      8. NOTICES AND COMMUNICATIONS. All notices, requests, demands, directions,
consents, waivers, approvals or other communications shall be in writing, in the
English language (or accompanied by an accurate English translation upon which
the Secretary shall have the right to rely for all purposes under this
Agreement) and shall be made or delivered in person or by registered or
certified mail, postage prepaid, addressed to the Guarantor or the Secretary as
provided below or to such other address as the Guarantor or the Secretary may
hereafter specify in a written notice to the other, and shall be effective upon
receipt by the addressee thereof. In any conflict over the meaning of this
Guaranty Agreement or any notices, directions or other communications pursuant
thereto, the English language shall control, notwithstanding any relevant
translations of the English version into any other language.

Guarantor:              PETRODRILL FIVE LIMITED
                        c/o Arias, Fabrega & Fabrega
                        P.O. Box 985
                        Omar Hodge Building
                        Wickham's Cay
                        Road Town, Tortola
                        British Virgin Islands

      With a copy to:   PETRODRILL ENGINEERING NV
                        K.P. van der Mandelelaan 38
                        3062 MB
                        Rotterdam (Brainpark)
                        The Netherlands

                        Secretary: SECRETARY OF TRANSPORTATION
                        c/o Maritime Administrator
                        Maritime Administration
                        U.S. Department of Transportation
                        400 Seventh Street, SW
                        Washington, DC 20590
                        Attention: Chief, Division of Ship Financing
                                   Contracts

      9. AMENDMENTS AND SUPPLEMENTS. No agreement shall be effective to change
or modify, supplement, amend or discharge in whole or in part this Guaranty
Agreement unless such agreement is in writing, signed by the Guarantor and the
Secretary.

      10. GOVERNING LAW. This Guaranty Agreement and the rights and obligations
of the parties hereto shall be construed, enforced, and governed by the laws of
the United States of America, but to the extent they are inapplicable, then by
the laws of the District of Columbia of the United States of America without
regard to its conflict of laws provision.

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      11. JURISDICTION AND CONSENT TO SUIT. Any proceeding to enforce this
Agreement may be brought in the Federal courts of the United States of America
located in the District of Columbia of the United States of America. The
Guarantor hereby irrevocably waives any present or future objection to such
venue, and for itself and in respect of any of its properties hereby irrevocably
consents and submits unconditionally to the exclusive jurisdiction of those
courts. The Guarantor further irrevocably waives any claim that any such court
is not a convenient forum for any such proceeding. The Guarantor agrees that any
service of process, writ, judgment or other notice of legal process shall be
deemed and held in every respect to be effectively served upon it in connection
with proceedings in the District of Columbia of the United States of America, if
delivered Sher & Blackwell, Suite 900, 1850 M Street, N.W., Washington D.C.
20036, which it irrevocably designates and appoints as its authorized agent for
the service of process in the District and Federal courts in the District of
Columbia of the United States of America. The Guarantor further agrees that
final judgment against it in any such action or proceeding arising out of or
relating to this Agreement shall be conclusive and may be enforced in any other
jurisdiction within or outside the United States of America by suit on the
judgment, a certified or exemplified copy of which shall be conclusive evidence
of that fact and of the judgment.

      12. PAYMENTS IN U.S. CURRENCY. This Guarantee is part of an international
financial transaction in which the specification of United States currency is of
the essence, and such currency shall be the currency of account in all events.
The payment obligations of the Guarantor hereunder shall not be discharged by an
amount paid in another currency, whether pursuant to a judgment or otherwise, to
the extent that the amount so paid on prompt conversion to such currency under
normal banking procedures does not yield after deduction of any and all fees,
taxes or any other charges imposed on the payment of such amount of United
States dollars then due. In the event that any payment by the Guarantor, whether
pursuant to a judgment or otherwise, upon conversion and transfer, does not
result in the payment of such amount of United States currency at the place such
amount is due, the Secretary shall be entitled to demand immediate payment of,
and shall have a cause of action against the Guarantor for, the additional
amount necessary to yield the amount then due. In the event the Secretary, upon
the conversion of such judgment into currency, shall receive (as a result of
currency exchange rate fluctuations) an amount greater than that to which it was
entitled, the Guarantor shall be entitled to immediate reimbursement of the
excess amount. The terms "U.S. currency" or the "dollars" or the symbol "$" as
used herein shall mean dollars in any coin or currency of the United States of
America.

      13 IMMUNITY. The Guarantor represents and warrants that it is subject to
civil and commercial law with respect to its obligations under this Agreement,
that the making and performance of this Agreement constitutes private and
commercial acts rather than governmental or public acts and that neither the
Guarantor nor any of its properties or revenues has any right of immunity on the
grounds of Sovereignty or otherwise from suit, court jurisdiction, attachment
prior to judgment, attachment in aid of execution of a judgment, set-off,
execution of a judgment or from any other legal process with respect to its
obligations under this Agreement. To the extent that the Guarantor may hereafter
be entitled, in any jurisdiction in which judicial proceedings may at any time
be commenced with respect to this Agreement to claim for itself or its revenues
or assets any

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such immunity, and to the extent that in any such jurisdiction there may be
attributed to the Guarantor such an immunity (whether or not claimed), the
Guarantor hereby irrevocably agrees not to claim and hereby irrevocably waives
such immunity. The foregoing waiver of immunity shall have effect under the
United States Sovereign Immunities Act of 1976.

      14. COUNTERPARTS. This Guaranty Agreement may be executed in one or more
counterparts. All such counterparts shall be deemed to be originals and shall
together constitute but one and the same instrument.

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      IN WITNESS WHEREOF, this Guaranty Agreement has been executed on the day
and year first above written.

                                          PETRODRILL FIVE LIMITED



                                          By: /s/ EARL W. MCNIEL
                                              ---------------------
                                              Name: Earl W. McNiel
                                              Title:  Treasurer

Attest:


/s/ ROBERT W. RANDALL
- - ----------------------
Name:Robert W. Randall
Title:  Secretary



ACKNOWLEDGED BY:

                                          UNITED STATES OF AMERICA
                                          SECRETARY OF TRANSPORTATION

                                          By:  MARITIME ADMINISTRATOR

(Seal)
                                          By: /s/ JOEL C. RICHARD
                                              -----------------------
                                              Secretary
                                              Maritime Administration

ATTEST:


/s/ LARRY MAIN
- - -----------------------
Assistant Secretary
Maritime Administration

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