EXHIBIT 10.251

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                            RBF EXPLORATION CO.
                 ________________________________________

                $200,000,000 SENIOR SECURED CLASS A1 NOTES
                 $50,000,000 SENIOR SECURED CLASS A2 NOTES
                 ________________________________________

                            ___________________

                          SUPPLEMENTAL INDENTURE
                               AND AMENDMENT

                       DATED AS OF February 1, 2000

                 CHASE BANK OF TEXAS, NATIONAL ASSOCIATION

                                 Trustee
                            ___________________

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     This  SUPPLEMENTAL INDENTURE AND AMENDMENT, dated as  of  February  1,
2000,  is  among RBF Exploration Co., a Nevada corporation (the  "Issuer"),
BTM  Capital Corporation, a Delaware corporation (the "Independent  Owner")
and Chase Bank of Texas, National Association, as Trustee (the "Trustee").

                               RECITALS

     WHEREAS, the Issuer and the Trustee entered into a Trust Indenture and
Security Agreement, dated as of August 12, 1999 (the "Indenture"), pursuant
to  which the Issuer has originally issued $200,000,000 in principal amount
of  Senior  Secured Class A1 Notes and $50,000,000 in principal  amount  of
Senior  Secured  Class  A2 Notes (collectively, the "Notes")  to  the  Note
Holders (as defined in the Indenture); and

     WHEREAS,  Section 13.8 of the Indenture provides that the  Issuer  and
the Trustee may amend or supplement the Indenture subject to the provisions
of Article 11 thereof; and

     WHEREAS,  the Issuer and the Independent Owner contemporaneously  with
the  execution  hereof have entered into that certain  Equipment  Sale  and
Funding  Agreement of even date herewith (the "Sale and Funding Agreement")
pursuant  to  which Issuer conveyed certain property and equipment  to  the
Independent Owner and entered into related financing arrangements; and

     WHEREAS,  the Issuer, Hyundai Corporation and Hyundai Heavy Industries
Co.,  Ltd. (collectively "Hyundai") entered into that certain Contract  for
Construction and Sale of Vessel (Hull No. HRBS6) (and also described by the
Issuer as RBS-8M and to be named the Deepwater Nautilus) dated November 14,
1997 (the "Construction Contract"), and whereas the Issuer, the Independent
Owner  and Hyundai contemporaneously with the execution hereof have entered
into  that  certain Novation Agreement (the "Novation Agreement")  of  even
date  herewith  (the Construction Contract, as modified  by  such  Novation
Agreement, being referred to as the "New Construction Contract"); and

     WHEREAS,  the Issuer and RBF Exploration II Inc., a Nevada corporation
("RBF  II")  entered  into that certain Construction Supervisory  Agreement
dated as of August 12, 1999 (the "Construction Supervisory Agreement"), and
whereas the Independent Owner, Issuer and RBF II contemporaneously with the
execution  hereof  have entered into that certain Construction  Supervisory
Agreement   of  even  date  herewith  (the  "New  Construction  Supervisory
Agreement"); and

     WHEREAS,  R&B  Falcon  Corporation, a Delaware corporation  ("Parent")
entered into that certain Performance Guarantee in favor of the Issuer, the
Sureties  and  the  Trustee dated as of August 12, 1999  (the  "Performance
Guarantee")  and  whereas contemporaneously with the execution  hereof  the
Parent has entered into that certain Performance Guarantee in favor of  the
Issuer,  the Independent Owner, the Sureties and the Trustee of  even  date
herewith (the "New Performance Guarantee"); and

     WHEREAS, RBF II, Travelers Casualty and Surety Company of America  and
American  Home Assurance Company (both, the "Sureties") entered  into  that
certain  Performance Bond dated August 18, 1999 (the "Original  Performance
Bond"),  and whereas in replacement of the Original Performance  Bond,  the
Independent  Owner, RBF II, Trustee, Issuer and the Sureties  have  entered
into  a  new  Performance Bond dated February 1, 2000 (the "New Performance
Bond"); and

     WHEREAS,  the Issuer entered into that certain Note Purchase Agreement
with  the  purchasers of notes identified therein dated as  of  August  12,
1999,  and  whereas contemporaneously with the execution hereof the  Issuer
has  entered  into certain First Amendment to Note Purchase  Agreements  of
even date herewith (the "Amendment to Note Purchase Agreements"); and

     WHEREAS,  pursuant to Section 11.2 of the Indenture, the Note  Holders
and  the  Sureties  (as  defined in the Indenture) have  consented  to  the
Trustee entering into this Supplemental Indenture; and

     WHEREAS, the Issuer and the Trustee now desire to amend and supplement
the  Indenture  to  consent  to  and provide  for  the  transactions  above
described and to allow for and make the Independent Owner a party thereto;

     NOW, THEREFORE, to comply with the provisions of the Indenture and  in
consideration of the above premises, the Issuer, the Independent Owner  and
the  Trustee covenant and agree for the equal and proportionate benefit  of
the respective Note Holders as follows:

                           ARTICLE 1

                            GENERAL

     Section  1.01.   This  Supplemental Indenture is supplemental  to  the
Indenture  and  does and shall be deemed to form a part of,  and  shall  be
construed in connection with and as part of, the Indenture for any and  all
purposes.   From this date, in accordance with Section 13.8 and Article  11
of the Indenture, and by executing this Supplemental Indenture, the parties
whose  signatures appear below are subject to all of the provisions of  the
Indenture and this Supplemental Indenture.

     Section  1.02.   This  Supplemental Indenture shall  become  effective
immediately  upon  its execution and delivery by each of  the  Issuer,  the
Independent Owner and the Trustee.

     Section  1.03.  Capitalized terms not otherwise defined  herein  shall
have the respective meaning ascribed thereto in the Indenture.

                           ARTICLE 2

                        TRUSTEE CONSENTS

     Section  2.01.  In accordance with the requirements of Section  8.3(c)
of  the Indenture and with the consent of the Required Holders, the Trustee
hereby  consents  to  the  novation  and replacement  of  the  Construction
Contract with the New Construction Contract under the Indenture. As of  the
date  hereof, the Construction Contract, as defined in the Indenture, shall
be  the  New  Construction  Contract and  the  definition  of  Construction
Contract  under  the Indenture shall be replaced in its entirety  with  the
definition of New Construction Contract as defined above.

     Section   2.02.   In  accordance  with  the  requirements  of  Section
8.3(f)(ii)  of the Indenture and at the direction of the Required  Holders,
the  Trustee  hereby consents to the novation and replacement  of  (a)  the
Construction  Supervisory  Agreement with the New Construction  Supervisory
Agreement, (b) the Performance Guarantee with the New Performance Guarantee
and (c) the Performance Bond with the New Performance Bond.  As of the date
hereof,  the Construction Supervisory Agreement, Performance Guarantee  and
Performance  Bond, as defined in the Indenture, shall be  respectively  the
New  Construction Supervisory Agreement, the New Performance Guarantee  and
New  Performance  Bond  and  the  definition  of  Construction  Supervisory
Agreement,  Performance Guarantee and Performance Bond under the  Indenture
shall be replaced in their entirety with the definition of New Construction
Supervisory  Agreement, New Performance Guarantee and New Performance  Bond
as defined above respectively.

     Section 2.03.  The Trustee does hereby

          (a)  release the security interest and lien granted by the Issuer
     under  the  Indenture upon the Equipment (as defined in the  Sale  and
     Funding Agreement) in consideration for this simultaneous grant by the
     Independent Owner pursuant to Article 3 hereof of a security  interest
     and  lien upon the same Equipment, provided that this clause (a)  does
     not constitute a release of the security interest and lien granted  by
     the  Issuer  under  the Indenture upon any other  part  of  the  Trust
     Estate;

          (b)   consent  to  the execution and delivery  of  the  Sale  and
     Funding Agreement and the Amendment to Note Purchase Agreements; and

          (c)   consent  to the exercise by the Independent  Owner  of  its
     rights  under clause 10 (Put Option) of the Sale and Funding Agreement
     (the "Put Option") to sell the Drilling Rig and Equipment, subject  to
     the security interest granted by the Independent Owner in favor of the
     Indenture  Trustee  in Article 3 hereof and the First  Preferred  Ship
     Mortgage  granted by the Independent Owner in favor of  the  Indenture
     Trustee and the terms and conditions of such section; provided that at
     the  time  of  such  transfer,  the  Trustee  is  furnished  with  the
     following, in form and substance satisfactory to the Trustee  and  the
     Rating Agencies:

        (i)     an assumption of the First Preferred Ship Mortgage  or  the
                execution  and delivery of a new mortgage executed  by  the
                purchaser  under the Put Option in substantially  the  same
                form as the First Preferred Ship Mortgage,

        (ii)    (x) an  amendment to the Indenture pursuant  to  which  the
                purchaser  under  the Put Option grants to  the  Trustee  a
                security  interest  in the Equipment on  substantially  the
                same  terms  as  the  security interest granted  under  the
                Indenture  on  the  date hereof together  with  appropriate
                financing  statements  to properly  perfect  such  security
                interest and (y) if at the time of such transfer,  the  New
                Performance   Bond  is  still  outstanding,  a   substitute
                Performance Bond in substantially the same form as the  New
                Performance Bond;

        (iii)   appropriate UCC  searches establishing  that  the  security
                interest granted under (ii) above is first priority,

        (iv)    opinions of  counsel  for the Issuer and,  as  appropriate,
                the  Sureties, satisfactory to the Trustee and  the  Rating
                Agencies  with  respect  to  the documents  provided  under
                clauses  (i) and (ii) above in substantially the same  form
                as  the  opinions  delivered by Gardere,  Wynne,  Sewell  &
                Riggs  L.L.P.,  Arias, Fabrega & Fabrega and the  Sureties'
                counsel  pursuant  to Section 3.01(E) of the  Amendment  to
                Note Purchase Agreements, and

        (v)     a certificate  or  certificates from appropriate  insurance
                brokers  that all required insurance remains in full  force
                and  effect with the purchaser under the Put Option as  the
                new owner of the Drilling Rig and Equipment.

      Section 2.04.  The Trustee hereby consents, to the extent required by
the  Indenture,  to  the  execution and delivery  of  any  other  documents
incidental to or required by the documents described in Sections 2.01, 2.02
and  2.03 hereof (all of such documents including, without limitation,  the
documents described in Sections 2.01, 2.02 and 2.03 hereof and any  Project
Document, together with this Supplemental Indenture, in each case as any of
the  foregoing items may be amended, supplemented or modified from time  to
time , the "Transaction Documents").

                           ARTICLE 3

              INDEPENDENT OWNER SECURITY INTEREST

     Section  3.01.   To  secure  the prompt and complete  payment  of  the
principal of, and interest and any applicable Make-Whole Amount on, all  of
the  Notes  issued and delivered and Outstanding, the payment of all  other
sums  owing under the Indenture and under all other Project Documents  (the
"Project  Indebtedness") and the performance of the covenants contained  in
the  Indenture and in all other Project Documents, and in consideration  of
the  premises  and of the covenants contained herein and  the  sum  of  One
Dollar  ($1.00) paid by the Trustee to the Independent Owner at  or  before
the  delivery  hereof,  the  receipt and  sufficiency  whereof  are  hereby
acknowledged,  the Independent Owner has hereby granted,  bargained,  sold,
conveyed,  assigned, transferred, mortgaged, affected, pledged,  set  over,
confirmed, granted a continuing security interest in, and hypothecated  and
does  hereby  grant,  bargain,  sell, convey, assign,  transfer,  mortgage,
affect, pledge, set over, confirm, grant a continuing security interest  to
the  Trustee  and  to any co-trustee or separate trustee  hereafter  acting
pursuant  to the Indenture, and to their respective successors and  assigns
in  trust  forever (subject to Section 12.1 of the Indenture), all  of  its
right,  title  and  interest  in,  to and  under  the  following  described
Properties  whether  now owned, existing or hereafter acquired  or  arising
(all  of  such  Properties,  including without  limitation  all  properties
hereafter  specifically  subjected to the liens of  the  Indenture  by  any
indenture supplemental thereto to which the Independent Owner has consented
in  writing,  being hereinafter collectively referred to as the "Additional
Trust Estate"):

          (a)  the Equipment and the Drilling Rig;

          (b)   all payments under and all accounts and General Intangibles
     generated  from or arising out of the New Construction  Contract,  the
     New Construction Supervisory Agreement, the New Performance Guarantee,
     the   Operation  and  Maintenance  Agreement,  the  Sale  and  Funding
     Agreement and the New Performance Bond together with any amendments or
     modifications  to any of the foregoing, excluding the  rights  of  the
     Independent  Owner and any other BTM Indemnitee to be  indemnified  as
     provided  under  Article  VII  of  the  New  Construction  Supervisory
     Agreement and to the extent it stands behind such indemnity,  the  New
     Performance  Guarantee (provided such exclusion does  not  impair  the
     rights  of  the Trustee or other parties now or hereafter entitled  to
     the benefits of such indemnity and the New Performance Guarantee), and
     the  right  of  the Independent Owner to exercise the  Put  Option  as
     provided by Section 2.03(c) above (provided the grant of this security
     interest  shall not prevent the Independent Owner from  enforcing  the
     obligations  of  the  Construction Supervisor (and  the  corresponding
     obligations under the New Performance Guarantee) under Section  2.5(x)
     or (y) of the Construction Supervisory Agreement);

          (c)   any  insurance  proceeds  (other  than  insurance  proceeds
     payable  to the Independent Owner under liability policies  for  tort,
     environmental and similar liabilities), condemnation proceeds and  the
     accounts, issues, profits, products, revenues and other income of  and
     from  the Drilling Rig and/or the Equipment and all the estate, right,
     title and interest of every nature whatsoever of the Independent Owner
     in and to the same and every part thereof; and

          (d)  all proceeds and products of any of the foregoing.

     This  security interest is granted under and pursuant to the Indenture
and all of the Additional Trust Estate is and shall be considered a part of
the Collateral and the Trust Estate under and pursuant to the Indenture and
this  Supplemental Indenture for all intents and purposes.  Subject to  the
provisions  of  Section 4.02 and Article 6 hereof, all  of  the  terms  and
conditions  of the Indenture with respect to the Collateral and  the  Trust
Estate  shall  apply to the Additional Trust Estate.  Specifically  and  in
this  connection the provisions of Sections 7.4 through and including  7.12
apply  to  the  Additional  Trust Estate and,  subject  to  the  terms  and
provisions  of  Article  6 hereof, the provisions  of  such  Sections  with
respect to the "Issuer" apply equally to the Independent Owner.

                           ARTICLE 4

                  INDEPENDENT OWNER COVENANTS

     Section  4.01.  Notwithstanding any of the foregoing consents  or  any
other terms hereof, the Independent Owner covenants and agrees that it will
not  assign or transfer any of its rights or obligations under any  of  the
Transaction  Documents and it will not assign or transfer the ownership  of
any  interest  in the Property that is part of the Additional Trust  Estate
(including,  without limitation, any interest in the Drilling Rig)  to  any
other  Person  (including,  without limitation, any  transfer  pursuant  to
clause  8 or clause 10.3 of the Novation Agreement or clause 9 of the  Sale
and Funding Agreement) without (i) the prior express written consent of the
Note Holders and (ii) prior written notice to each Rating Agency; provided,
however, the Independent Owner shall have the right, without consent of the
Note  Holders  or the Trustee, to exercise the Put Option  as  provided  by
Section 2.03(c) above.

     Section  4.02.   Subject  to the terms and  provisions  of  Article  6
hereof,  the Independent Owner covenants and agrees that until  payment  is
made  in  full  of all of the Notes and all other amounts  payable  by  the
Issuer under the Indenture or secured thereby, the Independent Owner shall:

               (a)  comply with and perform the following:

               A.   The  Independent Owner will promptly give  the  Trustee
                    and the Sureties notice of any litigation or proceeding
                    against  or  adversely affecting the  Additional  Trust
                    Estate   or   any  part  thereof  (including,   without
                    limitation,  any  attachment,  arrest,  levy  or  other
                    detention  of  the  Drilling Rig) and  of  all  claims,
                    judgments,  Liens or other encumbrances  affecting  the
                    Additional Trust Estate if the aggregate value of  such
                    claims,   judgments,   Liens  or   other   encumbrances
                    affecting  such  Property shall exceed  $1,000,000,  of
                    which  a  Responsible Officer of the Independent  Owner
                    has actual knowledge.

               B.   The  Independent Owner will promptly notify the Trustee
                    in  writing of any threatened action, investigation  or
                    inquiry  by  any  Governmental  Authority  of  which  a
                    Responsible Officer of the Independent Owner has actual
                    knowledge  in  connection with any  Environmental  Laws
                    with  respect  to the maintenance, use or operation  of
                    the    Drilling   Rig,   excluding   routine   testing,
                    inspections and corrective action.

               C.   Provided the Independent Owner is provided with notice,
                    documents  and  instruments  as  provided  in   Section
                    6.01(a)(A)  hereof, the Independent Owner will  execute
                    such  documents and instruments as required to promptly
                    cure  any  defects  in  the  creation,  execution   and
                    delivery  of any of the Transaction Documents to  which
                    it  is a party and all such other documents, agreements
                    (including,   without   limitation,   account   control
                    agreements)   and  instruments  to   comply   with   or
                    accomplish  the covenants and agreements of the  Issuer
                    or  the  Independent Owner in the Transaction Documents
                    or  to  further  evidence or more  fully  describe  the
                    Additional Trust Estate or to correct any omissions  in
                    the  Transaction Documents, or to state more fully  the
                    security  obligations set out herein or in any  of  the
                    other Transaction Documents, or to perfect, protect  or
                    preserve  any Liens created pursuant hereto or  any  of
                    the   other  Transaction  Documents,  or  to  make  any
                    recordings  or obtain any consents as may be  necessary
                    or  appropriate in connection therewith.  Further, upon
                    being furnished with notice, documents and instruments,
                    from  time  to time, as provided in Section  6.01(a)(A)
                    hereof, the Independent Owner will promptly execute and
                    deliver  or  cause  to  be executed  or  delivered  all
                    further  instruments and documents and take all further
                    action  that may be necessary or desirable or that  the
                    Trustee may request in order to (a) perfect and protect
                    the  Liens and other rights created or purported to  be
                    created  hereby and by the other Transaction  Documents
                    and  the first priority of such Liens and other rights;
                    (b)  enable  the  Trustee to exercise and  enforce  its
                    rights  and  remedies  hereunder  in  respect  of   the
                    Collateral; or (c) otherwise effect the purposes of the
                    Indenture, including, without limitation: executing and
                    filing  such  supplements to  the  Indenture  and  such
                    financing  or  continuation statements  (or  amendments
                    thereto)  as may be necessary or desirable or that  the
                    Trustee may reasonably request in order to perfect  and
                    preserve  the Liens created or purported to be  created
                    hereby or thereby; and

               D.   The  Independent Owner will not create, incur or suffer
                    to exist any Owner Lien upon any of the Trust Estate.

               E.   In the event any of the Trust Estate becomes subject to
                    any Owner Lien, it will promptly, at its expense, cause
                    such  Owner  Lien  or  Owner  Liens  to  be  completely
                    released,   discharged   and  removed.    Further,   in
                    connection herewith in the event a Responsible  Officer
                    of  the  Independent Owner has actual knowledge of  any
                    event  or  circumstance, including without  limitation,
                    any   circumstance   involving  any   Plan   sponsored,
                    maintained  or contributed to by the Independent  Owner
                    or  any  ERISA  Affiliate thereof,  including,  without
                    limitation,  any  ERISA  Event  with  respect  to   the
                    Independent Owner or any ERISA Affiliate thereof  which
                    event  or circumstance could reasonably be expected  to
                    cause  an  Owner  Lien to attach to any  of  the  Trust
                    Estate,  it  will  give prompt notice  thereof  to  the
                    Trustee.   In the event an Owner Lien attaches  to  any
                    part  of  the Trust Estate and such Lien is not removed
                    by  the Independent Owner as required by this clause E,
                    within  5  Business  Days  following  receipt  by   the
                    Independent Owner of notice thereof from the Issuer  or
                    the  Indenture  Trustee, the Issuer and  the  Indenture
                    Trustee shall each have the right to take all necessary
                    action  to cause such Owner Lien to be removed and  the
                    Independent Owner shall promptly reimburse  the  Issuer
                    and/or  Trustee for all costs and expenses incurred  by
                    them in connection with such action.

               F.   Solely with respect to the  Additional Trust Estate in-
                    cluding,  without  limitation,  the  Drilling  Rig, the
                    Construction  Contract, Refundment Guaranty, Construct-
                    ion Supervisory  Agreement,  Performance  Guaranty  and
                    Performance  Bond,  the Independent Owner  will  comply
                    with  and perform  the covenants of the  Issuer  as  if
                    references  to   the  Issuer  were  references  to  the
                    Independent Owner  under Sections 9.5, 9.7 and  9.11 of
                    the Indenture.  For  this purpose, the term "Issuer" in
                    Sections  9.5,  9.7  and 9.11 shall be deemed  to  mean
                    "Independent Owner".

               G.   The  Independent Owner will comply with and perform the
                    covenants   of  the  Issuer  under Sections 9.12, 9.18,
                    9.19  and   9.20  of the Indenture as if the references
                    therein   to   the  "Issuer"  were  references  to  the
                    "Independent Owner".

               H.   The  Independent Owner will comply with and perform the
                    covenants  of  the  Issuer under Section  9.16  of  the
                    Indenture as if references therein to the "Issuer" were
                    references to the "Independent Owner" except  that  the
                    Independent Owner shall not be required to  notify  the
                    Note Holders under such Section.

          (b)    enter  into  the  Sale  and  Funding  Agreement,  the  New
     Construction Contract, the New Construction Supervisory Agreement, the
     New  Performance Guarantee and the New Performance Bond and shall  not
     agree to any amendments, modifications or waivers of the terms thereof
     without express written consent of the Trustee;

          (c)   execute  and  deliver  the First  Preferred  Ship  Mortgage
     immediately upon delivery of the Drilling Rig pursuant to the terms of
     the  New  Construction  Contract and, in this  connection,  RBFE  will
     present  the Independent Owner with the First Preferred Ship  Mortgage
     document for execution.

          Notwithstanding  the foregoing, to the extent  that  any  of  the
     covenants  in  this  Section 4.02 requires the  Independent  Owner  to
     execute documents and instruments presented to it by the Issuer or the
     Indenture  Trustee  (which documents or instruments  by  their  nature
     require the signature thereto of the owner of the Drilling Rig  and/or
     the  Equipment  and  may not be signed, whether  or  not  a  power  of
     attorney has been granted by the owner of the Drilling Rig and/or  the
     Equipment,  by the Issuer or any other person or entity on  behalf  of
     the  Independent Owner), the Independent Owner's obligation to execute
     any such document or an instrument is conditional upon the Issuer, the
     Construction  Supervisor or the Indenture Trustee having  given  prior
     notice  in  writing  to  the Independent Owner to  execute  the  same,
     accompanied by such document or instrument.

     Section 4.03.  The Independent Owner agrees that it will not take  any
action  (i) which it knows to be contrary to covenants and other terms  and
provisions of the Indenture, the First Preferred Ship Mortgage or any other
Transaction Document or (ii) which it knows will inhibit the performance of
such covenants, terms and provisions by the Issuer or otherwise.

     Section  4.04.   Subject  to the terms and  provisions  of  Article  6
hereof,  to the extent any action on the part of the Independent  Owner  is
required  for  the Issuer's compliance with any covenant or other  term  or
provision  of  the Indenture, First Preferred Ship Mortgage  or  any  other
Transaction  Document, the Independent Owner will take such action  at  the
direction of the Issuer or the Trustee and at the expense of the Issuer.

     Section  4.05.   Subject  to Article 6 hereof, the  Independent  Owner
hereby  assumes and agrees to pay as and when due the Project Indebtedness.
The  Independent Owner agrees that any and all payments and other  proceeds
paid  or  payable from or under the Additional Trust Estate shall  be  paid
into  the Collection Account established under Section 4.3 of the Indenture
and applied as provided therein.  Notwithstanding the foregoing, the Issuer
remains fully and completely liable to pay the Project Indebtedness as  and
when due.

     Section  4.06    The  Independent  Owner  agrees  that  it  will  not,
otherwise  than pursuant to its rights under the Transaction  Documents  or
which  may exist under applicable law (and then subject to any restrictions
on  the  exercise  of  those rights under the Transaction  Documents),  and
except  as may be required by law, interfere with the quiet use, possession
and  quiet enjoyment of the Drilling Rig by SDDI, the Issuer or any of  its
or their Affiliates.

                           ARTICLE 5

                    AMENDMENTS TO INDENTURE

     Section  5.01.  The Granting Clause of the Indenture is hereby amended
by  deleting the last word "and" from clause (f), by deleting all of clause
(b) and clause (g) and by adding new clauses (b), (g) and (h) as follows:

           "(b)  All  accounts,  General  Intangibles  (including,  without
     limitation,   the  Construction  Contract,  the  SDDI  Contract,   the
     Construction  Supervisory  Agreement, the  Operation  and  Maintenance
     Agreement,  the  Performance Guarantee, the Refundment Guarantee,  the
     Sale  and  Funding  Agreement and the Performance Bond),  instruments,
     chattel  paper and documents, deposit accounts and investment property
     (including, without limitation, all Permitted Investments)  now  owned
     or hereafter acquired;

          (g)   Any  and  all  security interests, express  or  implied  by
     operation  of  law,  that the Issuer receives or is  deemed  to  have,
     securing  the obligations of the Independent Owner under the Sale  and
     Funding  Agreement and any and all other documents executed or assumed
     by  the  Independent Owner in connection therewith  (the  "Independent
     Owner Security"); and

          (h)  All proceeds and products of the foregoing."

     Section  5.02.  (a) Section 1.1 of the Indenture is hereby amended  by
adding  the  following  new  definitions where alphabetically  appropriate,
which read in their entirety as follows:

          Equipment  has  the  meaning set out  in  the  Sale  and  Funding
     Agreement  and the term Equipment to include, without limitation,  all
     equipment,  inventory, fixtures and other goods in all forms,  whether
     now  or hereafter existing which are on or used in connection with the
     Drilling  Rig, and all parts thereof, all accessions thereto  and  all
     replacements and substitutions therefor.

          Independent  Owner  shall mean BTM Capital Corporation,  and  its
     successors   and  permitted  assigns,  as  owner  of  the   Equipment,
     Construction Contract and Drilling Rig.

          Independent Owner Security has the meaning set out in clause  (g)
     of the Granting Clause hereof.

          Owner  Lien  means any Lien on or with respect to the  Additional
     Trust  Estate  which is not permitted by the terms of the  Transaction
     Documents  and which results from (i) nonpayment by Independent  Owner
     or any shareholder of Independent Owner or any Affiliate of any of the
     foregoing (the "Owner Parties"), of any tax, assessment or like charge
     imposed  on  any Owner Party, other than any tax, assessment  or  like
     charge  the  payment  of  which is the obligation  of  Issuer  or  any
     Affiliate  of  Issuer under this Supplemental Indenture or  any  other
     Transaction  Documents; (ii) claims against or acts and  omissions  of
     any  Owner  Party  arising out of events or conditions  that  are  not
     related  to the transactions contemplated by the Transaction Documents
     or  are  in  violation of any of the obligations of Independent  Owner
     under  any  of  the terms of the Transaction Documents;  (iii)  claims
     against any Owner Party arising out of any transfer (whether voluntary
     or  involuntary) by such Owner Party of any portion of its interest in
     the  Additional  Trust  Estate  or its rights  under  the  Transaction
     Documents  that  is neither permitted under the Transaction  Documents
     nor  consented to in writing by the Trustee; or (iv) any other act of,
     claim  against  or lien created by any Owner Party including,  without
     limitation,  any  lien attaching by reason of the Independent  Owner's
     participation  in  any  Multiemployer Employee Benefit  Plan,  or  any
     Person  claiming by, through or under any Owner Party, that is neither
     permitted  under the terms of the Transaction Documents nor  consented
     to in writing by the Indenture Trustee.

          Sale  and  Funding  Agreement has the  meaning  set  out  in  the
     Supplemental Indenture.

          Supplemental  Indenture  shall  mean  that  certain  Supplemental
     Indenture and Amendment dated as of February 1, 2000, executed by  the
     Issuer, the Independent Owner and the Trustee.

          Transaction Documents has the meaning set out in the Supplemental
     Indenture."

          (b)  The definition of "Note Purchase Agreement in Section 1.1 of
     the Indenture is amended by the addition at the end of such definition
     of the words "as amended by First Amendment to Note Purchase Agreement
     dated  February  1,  2000  and as the same  may  be  further  amended,
     supplemented or modified from time to time."

           (c)  The definition of "Project Documents" in Section 1.1 of the
     Indenture  is  amended  by (i) the addition of  the  words  "Sale  and
     Funding  Agreement" after the phrase "(as defined in the Note Purchase
     Agreement),"  and  (ii)  the addition of the words  "as  any  of  such
     Project  Documents may be amended, supplemented or modified from  time
     to time" at the end of such definition.

           (d)   The  definition of "Governmental Authority" is amended  by
     inserting  the words ", Independent Owner" after the word "Parent"  in
     the last line thereof.

     Section 5.03.  Clauses (j) and (o) of Section 7.1 of the Indenture are
hereby amended to hereafter read in their entirety as follows:

          "  (j)      Parent, SDDI, Royal Dutch Shell, RBF II,  Independent
     Owner  (but  only  with  respect to (d), (e)  or  (f))  or,  prior  to
     satisfaction  of the Operational Period Conditions Precedent,  one  of
     the Sureties takes, suffers or permits to exist with respect to itself
     any  of the events or conditions of the type referred to in paragraphs
     (d), (e), (f) or (i) hereof; or

          (o)   The  Issuer  or  the Independent Owner,  whichever  is  the
     registered  owner of the Drilling Rig, shall fail to execute,  or,  in
     the  case  of  the Issuer (or the Issuer on behalf of the  Independent
     Owner),  deliver  and  permanently record  the  First  Preferred  Ship
     Mortgage  and the Issuer shall fail to deliver the opinion of Issuer's
     counsel  in  the form of Annex E hereto upon delivery of the  Drilling
     Rig by Hyundai under the Construction Contract; or"

     Section 5.04.  The period at the end of clause (p) to Section  7.1  of
the Indenture is changed to "; or", and a new clause (q) is hereby added to
Section 7.1 of the Indenture to hereafter read as follows:

          "  (q) Any default occurs in the covenants or obligations of  the
     Independent  Owner  under  the Supplemental  Indenture  or  the  First
     Preferred  Ship  Mortgage or the Trustee receives a  notice  from  the
     Independent  Owner  pursuant  to  the  second  sentence   of   Section
     4.02(a)(E) of the Supplemental Indenture."

     Section  5.05   The occurrence and existence of any Event  of  Default
hereunder  or under any other Transaction Document by or on behalf  of  the
Independent  Owner shall not prevent the Independent Owner from  exercising
its  Put Option under the Sale and Funding Agreement or limit, restrict  or
condition  its  rights to the Put Option as permitted  herein  in  any  way
whatsoever subject in each case to compliance with Section 2.03(c) above.

     Section  5.06.  Section 8.3(d) of the Indenture is amended by deletion
of  the words "United States of America" therein and replacing those  words
with  "Republic of Panama" and by deletion of the words "U.S.  Coast  Guard
National  Vessel Documentation Center" and replacing those words  with  the
words "Public Registry of the Republic of Panama".

     Section 5.07   A new Section 9.21 is hereby added to read as follows:

           "9.21      Issuer  Action Regarding Independent Owner  Security.
     The  Issuer  shall  not  take any action under the  Independent  Owner
     Security without the written consent of the Trustee."

     Section 5.08   Annex E to the Indenture is amended and replaced in its
entirety by Annex E hereto.

      Section 5.09.  Section 13.3 of the Indenture is amended by adding the
following notice provision following the mail address of the Trustee:

          If to the Independent Owner:

          If by mail:
          BTM Capital Corporation
          125 Summer Street
          Boston, MA 02110
          Attention:  Senior Vice President - Administration

                           ARTICLE 6

             LIABILITY OF INDEPENDENT OWNER LIMITED

     Section  6.01.  Notwithstanding any of the other terms and  provisions
hereof or under the Indenture, it is understood and agreed as follows:

          (a)   Without  limitation of any other provision of this  Section
     6.01, and notwithstanding any provision of any Transaction Document to
     which the Independent Owner is a party which may be to the contrary or
     otherwise  inconsistent herewith, all obligations and  duties  of  the
     Independent  Owner under the Indenture (including, without limitation,
     this  Supplemental Indenture), the First Preferred Ship Mortgage,  the
     New Construction Contract, the New Construction Supervisory Agreement,
     and all other Transaction Documents to which the Independent Owner  is
     a  party, other than the Sale and Funding Agreement (all of which  are
     the  "Assumed  Obligations") shall, without releasing the  Independent
     Owner  from its obligations and duties, be performed on behalf of  the
     Independent  Owner  by  the  Issuer (or an Affiliate  of  the  Issuer,
     designated  from  time  to time by the Issuer) (in  reference  to  the
     Assumed Obligations, the "Assuming Party").

          The  Assumed  Obligations shall include, without limitation,  all
     obligations with respect to the construction, maintenance,  operation,
     insurance,  compliance with law, inspection, preservation,  protection
     and  transfer  or  other  disposition of  the  Drilling  Rig  and  any
     component or part thereof and any monetary obligations with respect to
     any of the foregoing.

          Notwithstanding the Assuming Party's obligation  to  perform  the
     Assumed  Obligations,  the Independent Owner  shall  be  obligated  to
     itself perform the following:

               (A)   The  execution and delivery with reasonable promptness
          to  the  Assuming  Party or the Trustee, at  the  sole  cost  and
          expense of the Assuming Party, such documents and instruments  as
          the Assuming Party or the Trustee may reasonably request in order
          for  the  Assuming Party to fully perform the Assumed Obligations
          on  behalf  of the Independent Owner, provided that the  Assuming
          Party  or the Trustee has provided the Independent Owner with  at
          least  10  Business  Days prior notice of such  request  and  the
          documents  and  instruments  or form  of  instruments  to  be  so
          executed,  and  provided  further that  the  Independent  Owner's
          execution and delivery of the same, either alone or in connection
          with  any  other  action relating thereto  to  be  taken  by  the
          Assuming  Party or another person or entity, will  not  have  the
          effect of increasing the liability of the Independent Owner.

               (B)  The making of the following payments to the Trustee, to
          the  extent  Independent Owner has actually received  funds  with
          respect thereto, for deposit into the Collection Account or  such
          other  account  as  RBF  Exploration Co. and  the  Trustee  shall
          jointly direct:

                    I.   Payments  which are part of or proceeds  from  the
               Additional Trust Estate;

                    II.   Payments made to the Independent Owner which  the
               Independent Owner and Trustee or the Independent  Owner  and
               the   Issuer  and  the  Trustee  jointly  determine  should,
               instead, under one or more Transaction Documents, be made to
               the  Trustee  or  another entity designated jointly  by  the
               Issuer and the Trustee; and

                    III.  Such other payments as may be due and owing under
               one  or more of the Transaction Documents, but only from and
               to the extent of such funds have been received by or as have
               been  made  available  to  the Independent  Owner  for  such
               purpose by the Issuer or any other Person, provided that the
               Independent  Owner  shall have no other responsibility  with
               respect to such payment or the monetary obligation to  which
               it  relates,  nor any obligation to reimburse  the  Assuming
               Party  in respect thereof, provided, however, nothing herein
               shall  limit or affect the enforceability of the  liens  and
               security interests granted pursuant to Article 3 hereof  and
               granted  or  to  be granted under the First  Preferred  Ship
               Mortgage or any other Transaction Document.

               (C)  Performance of the covenants under Article 4 hereof and
          Section 8.8 of the New Construction Supervisory Agreement.

               (D)   Taking  such  other  actions  as  may  reasonably   be
          requested  by RBF Exploration Co. or the Indenture Trustee  which
          are  not referred to above in this clause (a) but which meet  all
          of  the following conditions:  they are necessary to be performed
          by  the  Independent Owner pursuant to the Transaction Documents,
          by  their  nature  they  may  not legally  be  delegated  by  the
          Independent  Owner to the Assuming Party, they are of  a  routine
          and  administrative  nature,  they  do  not  involve  substantial
          additional undertakings by the Independent Owner, and they do not
          involve costs as to which the Independent Owner is not secured to
          its reasonable satisfaction.


           (b)  Neither the Trustee, any Note Holder nor any other party to
     a  Transaction Document nor any of their successors or assigns,  shall
     have  any  claim,  remedy or right to proceed against the  Independent
     Owner  for payment of any deficiency or any other sum owing on account
     of  the  indebtedness evidenced by any Note or for the payment of  any
     other unpaid obligation hereunder or thereunder or for the payment  of
     any  liability  resulting  from  the  breach  of  any  representation,
     covenant,  agreement  or  warranty of any  nature  whatsoever  in  the
     Indenture,  this  Supplemental Indenture or in any  other  Transaction
     Document  or  in  any  instrument  or  certificate  executed  by   the
     Independent Owner in connection herewith or therewith, from any source
     other  than  the  Trust  Estate  including,  without  limitation,  the
     Drilling   Rig  and  the  income  and  proceeds  (including,   without
     limitation,  insurance  and condemnation proceeds)  thereof;  and  the
     Issuer,  the  Trustee, each Note Holder and each other  party  to  any
     Transaction  Document shall be entitled to look solely  to  the  Trust
     Estate  including, without limitation, the Drilling Rig and the income
     and   proceeds   (including,   without   limitation,   insurance   and
     condemnation  proceeds) thereof, and waive and  release  any  personal
     liability  of the Independent Owner, for and on account  of  any  such
     deficiency,  indebtedness, unpaid obligations or any  such  liability,
     provided, however, that nothing herein contained shall limit, restrict
     or  impair  the  Indenture Trustee's or the  Note  Holders'  right  to
     accelerate  the  maturity  of the Notes upon  an  Indenture  Event  of
     Default,  to  bring suit and obtain a judgment against the Independent
     Owner  provided execution thereof shall be limited to the Trust Estate
     including,  without limitation, the Drilling Rig and  any  income  and
     proceeds  (including, without limitation, insurance  and  condemnation
     proceeds)  in  respect thereof or to exercise all rights and  remedies
     provided  under  each Note or under the Transaction Documents   or  to
     otherwise   realize   upon  the  Trust  Estate,   including,   without
     limitation,  the  Drilling Rig and provided  further,  nothing  herein
     shall limit the liability of the Independent Owner for the following:

          1.   To  the  extent  that  there has been  an  express  judicial
               determination  of  a  court  having  jurisdiction  over  the
               Independent  Owner and the relevant subject matter,  or  the
               Independent  Owner has expressly admitted in  writing,  that
               any  resulting  losses or damages have been  caused  by  the
               gross  negligence or willful misconduct of  the  Independent
               Owner  or  any other Owner Party such  judgment being  final
               and  being  or  having become subject to no further  appeals
               therefrom (provided that if such court is the U.S.  District
               Court  for  the  Southern District  of  New  York,  a  final
               judgment of such court even though such judgment is  subject
               to  appeal,  it  being understood that if such  judgment  is
               reversed  or  vacated  on such appeal, gross  negligence  or
               willful misconduct shall be deemed not to have been adjudged
               by such District Court).

          2.   breach  of  Section  4.02(a)(D) or (H) or any  reimbursement
               obligation under Section 4.02(E),

          3.   breach of Section 4.06,

          4.   failure of an Independent Owner representation under  clause
               (d) of this Section 6.01, or

          5.   default  by  the  Independent Owner in  its  obligations  to
               execute  and  deliver  any documents conveying  or  granting
               interests in the Additional Trust Estate in accordance  with
               Sections  6.01  and  7.01 hereof or  any  other  Transaction
               Document.

           (c)   No party (other than the Independent Owner itself) to this
     Supplemental Indenture or the other Transaction Documents to which the
     Independent Owner is a party shall have any claim, remedy or right  to
     proceed  against  any  incorporator or any  past,  present  or  future
     subscriber  to  the  capital  stock of,  or  stockholder,  officer  or
     director  of,  the  Independent  Owner  (each  such  person  being   a
     "Protected Person") with respect to any obligations under any  of  the
     Transaction   Documents,  whether  by  virtue  of  any  constitutional
     provision, statute or rule of law or by enforcement of any penalty  or
     assessment or otherwise, in respect of any claim it might have against
     the  Independent  Owner or in respect of any  act  or  omission  of  a
     Protected  Person,  and any such Protected Person  may  rely  on  this
     Section 6.01(c) to that extent.

           (d)   The  Independent Owner shall not be  responsible  for  any
     recitals  in the Indenture, this Supplemental Indenture or  any  other
     Transaction Document, nor shall it be bound to ascertain or inquire as
     to  the  performance  or  observance of any  covenants  or  agreements
     contained  herein  or  therein (other than those  of  the  Independent
     Owner),  or  for the satisfaction of any condition in any contract  to
     which  it  is  not  a party (including, without limitation,  the  SDDI
     Contract).    Except  as  expressly  provided  in  this   Supplemental
     Indenture, the Independent Owner shall be under no obligation to  take
     any action to protect, preserve or enforce any rights with respect  to
     the  Additional Trust Estate nor to take any action which may  involve
     pecuniary  loss,  liability  or expense  unless  it  shall  have  been
     provided with reasonable security or indemnity reasonably satisfactory
     to  the  Independent  Owner against the same.  The  Independent  Owner
     makes  no  representation  or  warranty  as  to  the  sufficiency   or
     enforceability  of the Indenture, this Supplemental Indenture  or  any
     other   Transaction  Document  (except  that  the  Independent   Owner
     represents and warrants that it has taken such corporate action as may
     be  necessary  to  duly authorize, execute and  deliver  such  of  the
     foregoing  as to which it is a party insofar as the internal  laws  of
     the  states  of New York and of its jurisdiction of incorporation  are
     concerned),  or  as  to the title (except that the  Independent  Owner
     represents and warrants that it has duly executed such instruments  as
     the  Issuer  has  provided to it purporting to  convey  title  to  the
     Drilling  Rig and any other portion of the Additional Trust Estate  to
     or  from  the  Independent  Owner, as the  case  may  be),  operation,
     merchantability or fitness for use or purpose, value, compliance  with
     specifications, condition, design, quantity, durability  or  otherwise
     with  respect  to  the  Drilling Rig  or  any  other  portion  of  the
     Additional  Trust Estate or any substitute therefor.  The  Independent
     Owner may consult with counsel, appraisers, engineers, accountants and
     other skilled persons to be selected by the Independent Owner, and the
     written advice of any thereof shall be full and complete authorization
     and protection in respect of any action taken, suffered or omitted  by
     it hereunder in good faith and in reliance thereon.

           (e)   The  obligations of the Independent Owner hereunder  shall
     cease  upon  the  transfer  of  its  interest  in  the  Trust  Estate,
     including,  without limitation, the Drilling Rig pursuant to  the  Put
     Option,  except  for any liabilities which may have accrued  prior  to
     such date pursuant to Section 6.01(b), provided however, such transfer
     shall not terminate or impair the liens and security interests granted
     by  Article 3 hereof and by the First Preferred Ship Mortgage and  any
     other Transaction Document.

                                 ARTICLE 7

                       CERTAIN ADDITIONAL AGREEMENTS

      Section 7.01   The Independent Owner and the Issuer agree that in the
event one or more of the option trigger events under Section 10 of the Sale
and  Funding Agreement have occurred and the Independent Owner has not  for
any  reason exercised the Put Option pursuant to clause 10.2 thereof within
30  days thereafter, the Independent Owner upon receipt of a written demand
that the Put Option be exercised ("Trustee Put Option Demand"), executed by
the  Trustee,  acting upon the request of any Note Holder, shall  sell  the
Drilling  Rig to the Issuer and the Issuer shall purchase the Drilling  Rig
from  the Independent Owner pursuant to Sections 10.4 and 10.5 of the  Sale
and  Funding  Agreement, such Trustee Put Option Demand to specify  a  date
(the  "Put Date") not less than 5 days and not more than 30 days after  the
date  of such demand upon which the transfer under clause 10.4 of the  Sale
and  Funding Agreement is to be effected.  In connection with any  exercise
of the Put Option, the Issuer will take or cause to be taken all action and
execute  or  cause  to  be executed such assumptions,  mortgages,  security
agreements  and other documents and cause the delivery of the  other  items
required  pursuant to Section 2.03(c) above and Section 10 of the Sale  and
Funding Agreement as may be required to consummate the sale of the Drilling
Rig pursuant to the exercise of the Put Option.

     Section  7.02.  Nothing in Article 4 or elsewhere in this Supplemental
Indenture  shall  relieve  the  Issuer  from  any  of  the  covenants   and
obligations  of the Issuer under and pursuant to the Indenture  as  amended
and  supplemented hereby and notwithstanding the ownership of the  Drilling
Rig  by  the  Independent Owner, the Issuer remains fully  responsible  and
liable  (including,  without limitation, as if it  was  the  owner  of  the
Drilling  Rig)  for the performance and compliance with all  covenants  and
obligations  of the Issuer under the Indenture as amended and  supplemented
hereby  and the First Preferred Ship Mortgage.  Further, the Issuer  hereby
covenants and agrees to perform all of the Assumed Obligations (as  defined
in  Article  6  hereof) and all other obligations of the Independent  Owner
under the Indenture as supplemented and amended hereby, the First Preferred
Ship Mortgage and under all other Transaction Documents.

     Section 7.03.  The Issuer agrees that it will not assign any of its
rights or interests in and to the Sale and Funding Agreement (except for
the security interest granted to the Trustee pursuant to the Indenture as
amended hereby) or agree to any amendment, modification or waiver of the
terms thereof without express written consent of the Trustee.

     Section 7.04.  Concurrently with the delivery of this Supplemental
Indenture, the Independent Owner has delivered to the Trustee in escrow and
the Trustee acknowledges receipt of a Bill of Sale in the form of Exhibit A
attached hereto, executed on behalf of the Independent Owner (the "Bill of
Sale").  The Trustee is hereby authorized to deliver the Bill of Sale to
the Issuer 5 Business Days after written notice to the Trustee and the
Independent Owner from a Responsible Officer of the Issuer certifying that
the Issuer requires the Bill of Sale to effect a sale contemplated by the
Sale and Funding Agreement and that such sale is being effected in
compliance with the terms and conditions of the Sale and Funding Agreement.
The Trustee shall have no duty or responsibility to determine the accuracy
or appropriateness of the Issuer's notice as aforesaid nor any liability as
a consequence of compliance therewith.

                           ARTICLE 8

                    MISCELLANEOUS PROVISIONS

     Section  8.01.   Except as expressly amended and supplemented  hereby,
the  Indenture is in all respects ratified and confirmed and all the terms,
conditions  and provisions thereof shall remain in full force  and  effect.
This  Supplemental  Indenture shall form a part of the  Indenture  for  all
purposes,  and every Note Holder heretofore or hereafter authenticated  and
delivered  under  the Indenture shall be bound hereby  and  all  terms  and
conditions  of  both  shall be read together as though  they  constitute  a
single  instrument, except that in the case of conflict the  provisions  of
this Supplemental Indenture shall control.

     Section  8.02.   Except  as otherwise expressly  provided  herein,  no
duties,  responsibilities or liabilities are assumed, or shall be construed
to  be  assumed,  by the Trustee by reason of this Supplemental  Indenture.
This Supplemental Indenture is executed and accepted by the Trustee subject
to  all  the terms and conditions set forth in the Indenture with the  same
force  and effect as if those terms and conditions were repeated at  length
herein and made applicable to the Trustee with respect hereto.

     Section   8.03.   THE  GOVERNING  LAW  PROVISIONS  OF  THE  INDENTURE,
INCLUDING  BUT NOT LIMITED TO THE APPLICATION OF THE LAWS OF THE  STATE  OF
NEW  YORK,  SHALL  ALSO  GOVERN AND BE USED TO CONSTRUE  AND  ENFORCE  THIS
SUPPLEMENTAL INDENTURE.

     Section  8.04.   The  parties may sign any number of  copies  of  this
Supplemental Indenture.  Each signed copy shall be an original, but all  of
such executed copies together shall represent the same agreement.

                     [NEXT PAGE IS SIGNATURE PAGE]

     IN  WITNESS  WHEREOF, the parties hereto have caused this Supplemental
Indenture to be duly executed, all as of the date first written above.


ATTEST:                            RBF EXPLORATION CO.

                                   By_________________________
Name:_____________________         Name:______________________
Title:____________________         Title:_____________________


ATTEST:                            BTM CAPITAL CORPORATION

                                   By_________________________
Name:_____________________         Name:______________________
Title:____________________         Title:_____________________


ATTEST:                            CHASE BANK OF TEXAS, NATIONAL ASSOCIATION

                                   By_________________________
Name:_____________________         Name:______________________
Title:____________________         Title:_____________________


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                                 EXHIBIT A

                               Bill of Sale

                                 [to come]

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                                  ANNEX E
                      [Opinion of Panamanian Counsel]