<PAGE>
                                                                   EXHIBIT 10.18


                             Dated 30 January 2003

                                 SOGELEASE B.V.
                                  as Sub-Lessor

                                     - and -

               GLOBALSANTAFE DRILLING COMPANY (NORTH SEA) LIMITED
                                  as Sub-Lessee

                         ------------------------------

                               SUB-LEASE AGREEMENT

                         ------------------------------

           in respect of a jack-up drilling unit known as "BRITANNIA"

                            WATSON, FARLEY & WILLIAMS
                                     LONDON

<PAGE>

                                      INDEX

<TABLE>
<CAPTION>
SECTION                                                                 PAGE
<S>                                                                     <C>
1     DEFINITIONS                                                          1

2     LEASING OF THE RIG                                                  11

3     COMMENCEMENT OF SUB-LEASE PERIOD                                    12

4     RENTALS                                                             12

5     PAYMENTS                                                            12

6     WITHHOLDING                                                         14

7     LOCATION, USE AND MAINTENANCE OF RIG                                15

8     PROTECTION OF THE SUB-LESSOR'S INTERESTS                            18

9     EXCLUSION OF LIABILITY                                              20

10    INSURANCE                                                           21

11    LOSS, DAMAGE AND REQUISITION                                        23

12    RETURN AND SALE OF THE RIG                                          25

13    TERMINATION                                                         26

14    GENERAL INDEMNITY                                                   30

15    COSTS, EXPENSES AND FEES                                            34

16    TAX INDEMNITY                                                       34

17    INCREASED COSTS                                                     36

18    RELEASE FROM ARREST                                                 37

19    RIGHTS AND WAIVERS                                                  38

20    NOTICES                                                             39

21    LAW AND JURISDICTION                                                40

22    ASSIGNMENT                                                          40

23    GENERAL                                                             41

SCHEDULE 1  THE RIG                                                       43

SCHEDULE 2  CERTIFICATE OF ACCEPTANCE                                     44

SCHEDULE 3  FINANCIAL SCHEDULE                                            45
</TABLE>

<PAGE>

<TABLE>

<S>                                                                       <C>
EXECUTION PAGE                                                            48
</TABLE>

<PAGE>

THIS SUB-LEASE AGREEMENT is dated 30 January 2003

BETWEEN:

(1)   SOGELEASE B.V., a company incorporated in The Netherlands having its main
      office at Rembrandt Tower, Amstelplein 1, 1096 HA, Amsterdam, The
      Netherlands (the "SUB-LESSOR", which expression includes its successors,
      permitted assignees and permitted transferees); and

(2)   GLOBALSANTAFE DRILLING COMPANY (NORTH SEA) LIMITED, a company incorporated
      in England and Wales (with company number 00782373) having its registered
      office at Lothing Depot, North Quay, Commercial Road, Lowestoft NR32 2TF
      (the "SUB-LESSEE" which expression includes its successors, permitted
      assignees and permitted transferees).

WHEREAS:

The Sub-Lessor is the lessee of the Rig under the terms of the Head-Lease. The
Sub-Lessee wishes to take the rig on sub-lease and the Sub-Lessor agrees to
sub-let the Rig to the Sub-Lessee upon the terms and conditions contained
herein.

IT IS HEREBY AGREED as follows:

1     DEFINITIONS

1.1 In this Sub-Lease, the following terms shall have the meanings given below:

      "ACCELERATION DATE" means either (i) the date on which a Termination
      Notice is served by the Sub-Lessor pursuant to Clause 13.1 (Termination
      Events) or (ii) the date on which a Voluntary Termination Notice expires;

      "AFFILIATE" means, in relation to a party, any other entity in which it
      possesses directly or indirectly the power to direct or cause the
      direction of the management and policies of the other person, whether
      through ownership of voting shares, by contract or otherwise, or which is
      under direct or indirect common control with, that party from time to
      time;

      "BUSINESS DAY" means any day (other than a Saturday or a Sunday) on which
      banks generally are open for business in London, New York and the
      Netherlands;

      "CERTIFICATE OF ACCEPTANCE" means a certificate in the form attached as
      Schedule 2 (Certificate of Acceptance) executed or to be executed by the
      Sub-Lessor and the Sub-Lessee;

      "CHANGE OF LAW" means, in each case after the date of this Sub-Lease:

      (a)   the implementation, introduction, abolition, withdrawal or variation
            of any applicable law, regulation, practice or concession or
            official directive, ruling, request, notice, guideline, statement of
            policy or practice statement by the European Union or any central
            bank or tax, fiscal, revenue, monetary, governmental, local,
            international, national or other competent authority or agency
            (whether or not having the force of law but in respect of which
            compliance by banks or other financial institutions or institutions
            of a similar nature to the Sub-Lessor in the relevant jurisdiction
            is generally customary); or

<PAGE>

      (b)   any change in any interpretation, or the introduction or making of
            any new or further interpretation, or any new or different
            interpretation of any applicable law, regulation, practice or
            concession or official directive, ruling, request, notice,
            guideline, statement of policy or practice statement by any court,
            tribunal, governmental, local, international, national or other
            competent authority or agency or the European Union or any central
            bank or tax, fiscal, revenue or monetary authority or agency
            (whether or not having the force of law but in respect of which
            compliance by banks or other financial institutions or institutions
            of a similar nature to the Sub-Lessor in the relevant jurisdiction
            is generally customary); or

      (c)   compliance with any new or different request or direction from the
            European Union or any central bank, tax, fiscal, regulatory
            monetary, revenue, governmental, local, international, national or
            other competent authority or agency (whether or not having the force
            of law but in respect of which compliance by banks or other
            financial institutions or institutions of a similar nature to the
            Sub-Lessor in the relevant jurisdiction is generally customary),

      and for the avoidance of doubt, any decision of a court which discloses a
      state of law such that any practice, concession, official direction or
      other statement of policy or interpretation lawfully made by any
      authority, organisation or agency referred to above ceases to be
      applicable or correct shall be deemed to be a withdrawal or abolition
      thereof;

      "CHARTER" means the bareboat charter dated 1 November 2002 and entered
      into between the Sub-Lessor and the Charterer in respect of the Rig as
      that bareboat charter may be amended from time to time or, as the case may
      be, any other bareboat charter which the Sub-Lessor or the Charterer may
      enter into from time to time in substitution therefor in accordance with
      the terms of the Sub-Lease;

      "CHARTERER" means GlobalSantaFe Drilling U.K. Limited, a company
      incorporated in Scotland with company number SC131375 having its
      registered office at Langlands House, Huntly Street, Aberdeen AB10 1SH or,
      as the case may be, any other person to whom the Sub-Lessee charters the
      Rig pursuant to a Charter;

      "COMPULSORY ACQUISITION" means requisition for title or other compulsory
      acquisition, requisition, appropriation, expropriation, deprivation,
      forfeiture or confiscation for any reason of the Rig by any Governmental
      Entity or other competent authority, whether de jure or de facto, but
      shall exclude requisition for use or hire not involving requisition for
      title;

      "DEFAULT RATE" means 2% per annum over LIBOR from time to time;

      "DOLLARS" and "US$" means the lawful currency for the time being of the
      United States of America;

      "ENCUMBRANCE" means any mortgage, charge, assignment by way of security,
      pledge, hypothecation, lien, right of set-off, retention of title
      provision, trust or flawed asset arrangement (for the purpose of, or which
      has the effect of, granting security) or any other security interest of
      any kind whatsoever, or any agreement, whether conditional or otherwise,
      to create, or which has the effect of creating, any of the same, or any
      agreement to sell or otherwise dispose of any asset;


                                       2
<PAGE>

      "ENVIRONMENT" means:

      (a)   any land including, without limitation, surface land and sub-surface
            strata, sea bed or river bed under any water (as defined below) and
            any natural or man-made structures;

      (b)   water including, without limitation, coastal and inland waters,
            surface waters, ground waters and water in drains and sewers; and

      (c)   air, including air within buildings and other natural and man-made
            structures above and below ground;

      "ENVIRONMENT CLAIM" means any written or oral notice from any person
      alleging any breach, contravention or violation of any Environmental Law
      or the existence of any liability or potential liability arising from any
      such breach, contravention or violation including, without limitation,
      liability to conduct, pay for or for damages in respect of, any
      investigation or audit, clean-up, redemption, administrative costs or
      charge or expense, damage to the Environment or any natural resource,
      property loss or damage, personal injury or any penalty, attaching or
      relating to the presence, emission, release or leak of any Hazardous
      Material in or to the Environment;

      "ENVIRONMENTAL LAW" means any or all applicable law (whether civil,
      criminal or administrative), common law, statute, statutory instrument,
      treaty, convention, regulation, directive, by-law, demand, decree,
      injunction, resolution, order or judgment (in each case having the force
      of law) and codes of practice or conduct circulars and guidance notes
      having legal or judicial import or effect, in each case of any
      Governmental Entity (whether now existing or hereafter promulgated) in any
      applicable jurisdiction relating to or concerning:

      (a)   pollution or contamination of the Environment;

      (b)   harm, whether actual or potential, to mankind and human sense, other
            living organisms and ecological systems;

      (c)   the generation, manufacture, processing, distribution, use
            (including abuse), treatment, storage, disposal, transport or
            handling of Hazardous Materials; and

      (d)   the emission, leak, release, spill or discharge into the Environment
            of noise, vibration, dust, fumes, gas, odours, smoke, steam,
            effluvia, heat, light, radiation (of any kind), infection,
            electricity or any Hazardous Material and any matter or thing
            capable of constituting a nuisance or any actionable tort or breach
            of statutory duty of any kind in respect of such matters;

      "ENVIRONMENTAL PERMITS" means, in relation to any person, all or any
      permits, licences, consents, approvals, ruling, variance, exemption,
      certificates, registrations and other authorisations and the filing of all
      notifications, reports and assessments required under any Environmental
      Law in connection with the conduct of such person's business and the
      ownership, use, exploitation or occupation of all of its property and
      assets;

      "FINANCIAL INDEBTEDNESS" means any indebtedness in respect of:-

      (a) moneys borrowed;


                                       3
<PAGE>

      (b)   any debenture, bond, note, loan stock or other security;

      (c)   any acceptance or documentary credit;

      (d)   receivables sold or discounted (otherwise than on a limited recourse
            basis);

      (e)   the acquisition cost of any asset to the extent payable before or
            after the time of acquisition or possession by the party liable
            where the advance or deferred payment is arranged primarily as a
            method of raising finance or financing the acquisition of that
            asset;

      (f)   a capital lease under FAS 13;

      (g)   any currency swap or interest swap, cap or collar arrangement or any
            other derivative instrument provided that for the purposes of Clause
            13.1(e) only the net amount payable shall be taken into account;

      (h)   any amount raised under any other transaction having the commercial
            effect of a borrowing or raising of money; or

      (i)   any guarantee, indemnity or similar assurance in respect of any of
            (a) to (h) above.

      "FINANCIAL SCHEDULE" means Schedule 3;

      "FIXTURE" means fixed to any land so as to become in law part of that land
      and including, without limitation, the Rig being treated as a fixture
      under English law (including without limitation the Capital Allowances Act
      2001);

      "GOVERNMENTAL ENTITY" means and includes (whether having a distinct legal
      personality or not) (i) any national government, political sub-division
      thereof or local jurisdiction therein, (ii) any board, commission,
      department, division, organ, instrumentality, court or agency of any
      entity referred to in (i) above, however constituted and (iii) any
      association, organisation or institution (international or otherwise) of
      which any entity mentioned in (i) or (ii) above is a member or to whose
      jurisdiction any of the foregoing is subject or in whose activities any of
      the foregoing is a participant;

      "GUARANTEE" means a guarantee and indemnity dated on or about the date
      hereof from the Guarantor in favour of the Sub-Lessor in respect of the
      obligations of the Sub-Lessee under this Sub-Lease and the other Lease
      Documents;

      "GUARANTOR" means GlobalSantaFe Corporation, a company incorporated under
      the laws of the Cayman Islands with its registered office c/o M&C
      Corporate Services Limited, PO Box 309 GT, Ugland House, South Church
      Street, George Town, Grand Cayman, Cayman Islands and having an office at
      15375 Memorial Drive, Houston, Texas
      77079-4101, USA;

      "GUARANTOR'S GROUP" means the Guarantor and any of its Affiliates;

      "GSF STANDARD" means the standards of operation, management and
      maintenance which the members of the Guarantor's Group adhere to from time
      to time in respect of drilling units comparable to the Rig which standards
      are at all times comparable to the standards of a reasonably prudent
      operator of oil rigs of the same type, age and condition as the Rig;


                                       4
<PAGE>

      "HEAD-LEASE" means the Head-Lease Agreement dated the same date as this
      Sub-Lease between the Head-Lessor (as lessor) and the Sub-Lessor (as
      lessee) in respect of the Rig;

      "HEAD-LESSOR" means the Sub-Lessee in its capacity as lessor under the
      Head-Lease or any Transferee (as defined in Clause 22.2 (Sub-Lessee));

      "INDEMNIFIED PERSONS" means the Sub-Lessor, any member of the sub-Lessor
      Group and their respective officers, directors, agents and employees;

      "ISM CODE" means the International Safety Management Code (including the
      guidelines on its implementation), adopted by the International Maritime
      Organization Assembly as Resolutions A.741(18) and A.788.19, as the same
      may be amended and supplemented from time to time;

      "LEASE DOCUMENTS" means this Lease, the Certificate of Acceptance, the
      Sub-Lease, the Certificate of Acceptance (as defined in this Sub-Lease),
      the Support Letter, the Guarantee, the Lessor Payment Letter, the Lessee
      Payment Letter and all other documents agreed in writing by the Lessor and
      the Lessee to be Lease Documents;

      "LEASING TERMINATION DATE" means the date on which the sub-leasing of the
      Rig terminates in accordance with Clause 12.2(b);

      "LOSS" or "LOSSES" means any liability, loss (including, without
      limitation, financial loss or liability), charge, claim, proceeding,
      damage, judgment, enforcement penalty, fine (including, without
      limitation, any penalty or fine arising under Environmental Law), fee,
      cost (including, without limitation, legal costs), lien, salvage, average
      and expense of whatsoever nature (but excluding any Tax or VAT, interest,
      penalty or fine in connection therewith) suffered or incurred by or
      imposed on any Indemnified Person from time to time in connection with
      this Sub-Lease or the other Lease Documents or the Rig or the transactions
      contemplated in this Sub-Lease or any other Lease Document;

      "NET SALE PROCEEDS" means the Sale Proceeds minus:

      (a)   the costs and expenses of the sale of the Rig in accordance with
            clause 12 of the Head-Lease (Return of the Rig); and

      (b)   VAT Irrecoverable on Sale;

      "OPERATOR" means any Affiliate of the Guarantor which has the day to day
      operational control of the Rig from time to time;

      "PAYMENT ACCOUNT DETAILS" means in relation to any payment to be made
      under or pursuant to this Sub-Lease or any Lease Document, the name,
      account number, sort code, account location (being an account in the
      United Kingdom) and other details specified by the payee and necessary to
      effect payment (by electronic means of transfer) to the payee;

      "PERMITTED ENCUMBRANCE" means:

      (a)   any Sub-Lessor Encumbrance;

      (b)   Encumbrances for Taxes for which the Head-Lessor or the Sub-Lessee
            is liable either not yet assessed or, if assessed, not yet due and
            payable or being contested in good faith by appropriate proceedings
            (and for the payment of which adequate


                                       5
<PAGE>

            reserves have been provided) so long as any such proceedings do not
            involve any reasonable likelihood of the sale, forfeiture or loss
            of, or of any interest in, the Rig (or any part thereof);

      (c)   Encumbrances (other than Encumbrances for Taxes) arising out of
            claims, judgments or awards against the Head-Lessor or the
            Sub-Lessee with respect to which at the time an appeal or proceeding
            for review is being prosecuted in good faith (and for the payment of
            which adequate reserves have been made or, when required in order to
            pursue such proceeding, an adequate bond has been provided) and for
            which there shall have been secured a stay of execution pending such
            appeal or proceeding for review so long as any such judgment, award
            or proceeding does not involve any reasonable likelihood of the
            sale, forfeiture or loss of, or of any interest in, the Rig (or any
            part thereof);

      (d)   any lien for salvage and any ship repairer's or outfitter's
            possessory lien or any lien for general average or for officers' or
            crew's wages not more than ten (10) Business Days outstanding
            arising in the ordinary course of trading or any other Encumbrance
            or contractual right of set-off arising by operation of law in the
            ordinary course of trading and in respect of obligations which are
            not overdue which in each case is not yet due and payable or is
            being contested in good faith by appropriate proceedings (and for
            the payment of which adequate reserves or an adequate bond have been
            provided) so long as any such proceedings or the continued existence
            of such Encumbrance do not involve any reasonable likelihood of the
            sale, forfeiture or the loss of, or of any interest in, the Rig (or
            any part thereof);

      (e)   the Lease Documents, the Charter and the Service Contract;

      (f)   any Encumbrance, the creation of which has been expressly permitted
            in writing by the Sub-Lessor;

      (g)   any Encumbrance in respect of claims which the Sub-Lessee
            demonstrates to the Sub-Lessor's satisfaction are then covered by
            insurance so long as the same do not create a reasonable likelihood
            of the sale or forfeiture or loss of, or of any interest in, the Rig
            (or any part thereof).

      "PREMIUM" means the amount of thirty seven million Dollars
      (US$37,000,000);

      "RELEASE" means an emission, spill, release or discharge into or upon the
      air, surface water, groundwater, or soils of any Hazardous Materials for
      which the relevant person has any liability under Environmental Law,
      except in accordance with a valid Environmental Permit;

      "RENTAL" means each amount of rent payable in relation to the Sub-Lease
      Period pursuant to Clause 4 (Rentals), as determined in accordance with
      the Financial Schedule as adjusted from time to time;

      "RENTAL PAYMENT DATE" means:

      (a)   in respect of the first Rental due under this Sub-Lease, 3rd
            February, 2003;

      (b)   in respect of the second Rental due under this Sub-Lease, 3rd
            February, 2004;

      (c)   in respect of the third Rental due under this Sub-Lease, 3rd
            February, 2005;

      (d)   in respect of the fourth Rental due under this Sub-Lease, 3rd
            February, 2006; and


                                       6
<PAGE>

      (e)   in respect of the fifth Rental due under this Sub-Lease, 5th
            February, 2007;

      "RENTAL PERIOD" means each period commencing on a Rental Payment Date and
      ending on the day before the next following Rental Payment Date or, in the
      case of the last such period, ending on the last day of the Sub-Lease
      Period;

      "REQUIRED INSURANCES" means the protection and indemnity insurance in
      respect of the Rig required to be maintained by the Sub-Lessee in
      accordance with Clause 10.1 (a);

      "REQUISITION COMPENSATION" means all sums of money or other compensation
      from time to time payable in respect of the Compulsory Acquisition of the
      Rig;

      "RIG" means the jack-up drilling unit known as "Britannia" and at the date
      of this Sub-Lease working over the Skiff Platform in the Southern North
      Sea of the United Kingdom continental shelf more fully described in
      Schedule 1, together with all equipment, furniture, and all other
      appurtenances owned by the Sub-Lessee in relation thereto (whether at the
      date of this Sub-Lease or later) but excluding consumable stores and
      provisions, rented equipment and equipment owned or rented by
      subcontractors and all replacements, renewals, improvements and
      substitutions (whether pursuant to the terms of this Sub-Lease or
      otherwise) and all additions and accessories thereto;

      "SHELL" means Shell UK Limited (trading as "Shell UK Exploration and
      Production");

      "SERVICE CONTRACT" means the service contract originally entered into
      between Shell and the Head-Lessor with a commencement date of 1 October
      2001 (and novated from the Head-Lessor to the Charterer by a novation
      agreement dated 1 November 2002) in respect of the operation and
      employment of the Rig as that contract has been and may further be amended
      from time to time or any other service contract which the Sub-Lessee or
      the Charterer may enter into from time to time in substitution therefor in
      accordance with the terms of this Sub-Lease;

      "START DATE" means the date of execution of the Certificate of Acceptance
      (as that term is defined in the Head-Lease) by both the Head Lessor and
      the Sub-Lessor (in its capacity as lessee under the Head-Lease);

      "STAMP DUTY" means all stamp duties as levied in the United Kingdom at the
      date hereof and imposed by the Stamp Act 1891 including any interest,
      penalty, surcharge or fine payable in respect thereof;

      "SUB-LEASE" means this Sub-Lease Agreement and the words "herein",
      "hereunder" and similar words and expressions shall be construed
      accordingly;

      "SUB-LEASE PERIOD" means a period of five (5) years commencing on the
      Start Date (or such shorter period as may be determined in accordance with
      the terms of this Sub-Lease;

      "SUB-LESSOR ENCUMBRANCES" means any Encumbrance on the Rig to the extent
      that it is solely attributable to or arises as a result of:

      (a)   claims against or affecting the Sub-Lessor (including any claim in
            relation to any other rig or vessel of which the Sub-Lessor is the
            owner or the lessee or demise charterer) and leased or chartered by
            it otherwise than to the Sub-Lessee or any other member of the
            Guarantor's Group) to the extent that it is not related to, or does
            not arise directly or indirectly as a result of the transactions
            contemplated by this Sub-Lease or any of the other Lease Documents
            but excluding any such claim to the extent that it is solely
            attributable to or arises as a result of any actions,


                                       7
<PAGE>

            omission, failure or breach, negligent or otherwise, of the
            Sub-Lessee or any other member of the Guarantor's Group; or

      (b)   acts or omissions of the Sub-Lessor to the extent not contemplated,
            required or permitted directly or indirectly as a result of the
            transactions contemplated by this Sub-Lease or any of the other
            Lease Documents but excluding any such act or omission to the extent
            that it is solely attributable or arises as a result of any action,
            omission, failure or breach, negligent or otherwise of the
            Sub-Lessee or any other member of the Guarantor's Group; or

      (c)   the non-payment of Taxes imposed upon the Sub-Lessor, other than
            those Taxes the subject of any indemnity in favour of the Sub-Lessor
            under the Lease Documents or where the liability to pay, or the
            amount of such Taxes is being disputed by the Sub-Lessee in good
            faith or those which are solely attributable to or arise as a result
            of any actions, omission, failure or breach, negligent or otherwise
            of the Sub-Lessee or any other member of the Guarantor's Group; or

      (d)   any act or omission of the Sub-Lessor constituting a breach by the
            Sub-Lessor of its obligations under this Sub-Lease or the other
            Lease Documents to the extent that it is not solely attributable to
            or does not relate to or arise directly or indirectly as a result of
            any action, omission, failure or breach, negligent or otherwise, of
            the Sub-Lessee or any member of the Guarantor's Group; or

      (e)   any act or omission of the Sub-Lessor which constitutes the wilful
            misconduct or recklessness with knowledge of the probable
            consequences,

      but excluding in any such case any Encumbrance which the Sub-Lessor is
      contesting in good faith by appropriate proceedings so long as such
      proceedings or the continued existence of the Encumbrance do not give rise
      to any reasonable likelihood of the sale, forfeiture or loss of, or of any
      interest in, the Rig (or any part thereof);

      "SUB-LESSOR GROUP" means the Sub-Lessor Parent and its Affiliates from
      time to time;

      "SUB-LESSOR PARENT" means Societe Generale, a French banking institution;

      "SUB-LESSOR'S DISPOSAL PROCEEDS" means following a sale of the Rig, the
      amount of Net Sale Proceeds to which the Sub-Lessor is entitled under the
      Head-Lease in respect of the disposal by any means of its interest in the
      Rig and its rights under the Head-Lease;

      "SUPPORT LETTER" means the support letter issued or to be issued by the
      Sub-Lessor Parent in favour of the Sub-Lessee in form and substance
      satisfactory to the Sub-Lessee;

      "TAXES" means all present and future taxes, levies, imposts, duties, fees
      or charges of any kind whatsoever including, without limitation,
      corporation, capital gains, income, gross receipt, franchise, transfer,
      sales, use, business, occupation, transaction, purchase, excise, personal
      property, real property, stamp, documentary, national insurance or other
      taxes) or any amount payable on account of or instalment payments in
      respect of or as security for any of the foregoing payable at the instance
      of or imposed by any governmental, taxing or fiscal authority whatsoever
      whether in the United Kingdom or elsewhere together with any penalties,
      additions, fines or interest relating to any of them and "TAX" and
      "TAXATION" and cognate expressions shall be construed accordingly;

      "TAX LIABILITY" means in respect of any person:

      (a)   any liability or any increase in the liability of that person to
            make any payment or payments of or in respect of Tax;


                                       8
<PAGE>

      (b)   the loss or setting off against income, profits or gains or against
            any liability to make a payment or payments of or in respect of Tax
            of any relief, allowance, deduction or credit (a "RELIEF") which
            would otherwise have been available to that person; and

      (c)   the loss or setting off against any liability to make a payment or
            payments of or in respect of Tax of a right to repayment of Tax
            which would otherwise have been available to that person.

      and in any case falling within (b) or (c) above the amount that is to be
      treated as a Tax Liability shall be determined as follows:-

      (i)   in a case which falls within (b) above and where the Relief that was
            the subject of the loss or setting off was or would have been a
            deduction from or offset against Tax, the Tax Liability shall be the
            amount of that Relief;

      (ii)  in a case which falls within (b) above and which involves the loss
            of a Relief which would otherwise have been available as a deduction
            from or offset against gross income, profits or gains the Tax
            Liability shall be the amount of Tax which would (on the basis of
            the Tax rates current at the date of the loss and assuming that the
            person has sufficient gross income, profits or gains to utilise the
            Relief) have been saved but for the loss of the Relief;

      (iii) in a case which falls within (b) above and which involves the
            setting off of a Relief which would otherwise have been available as
            a deduction from or offset against gross income, profits or gains,
            the Tax Liability shall be the amount of Tax which has been or will
            be saved in consequence of the setting off;

      (iv)  in a case which falls within (c) above, the Tax Liability shall be
            the amount of the repayment that would have been obtained but for
            the loss or setting off.

      For the purposes of this definition, any question of whether or not any
      right to repayment of Tax has been lost or set-off, and if so, the date on
      which that loss or set-off took place or would otherwise have taken place,
      shall be determined by the Sub-Lessor in its absolute discretion.

      "TERMINATION EVENT" means any of the events so specified in Clause 13.1
      (Termination Events);

      "TERMINATION NOTICE" has the meaning given to it in Clause
      13.1(Termination Events);

      "TERMINATION PAYMENT DATE" means:

      (a)   following the issue of a Voluntary Termination Notice, the date on
            which the Voluntary Termination Notice expires; or

      (b)   where a Termination Notice has been given by the Sub-Lessor to the
            Sub-Lessee pursuant to Clause 13.1(Termination Payment), the date
            falling five (5) Business Days after the date of receipt by the
            Sub-Lessee of the Termination Notice;

      "TERMINATION SUM" means, with respect to any date, or amount calculated
      for such date in accordance with paragraph 2 (Termination Payment) of the
      Financial Schedule;

      "TOTAL LOSS" means:


                                       9
<PAGE>

      (a)   actual or constructive or compromised or arranged or agreed total
            loss of the Rig; or

      (b)   the destruction or damage beyond economic repair of the Rig, or the
            Rig being otherwise rendered or declared permanently unfit for
            normal use for any reason whatsoever; or

      (c)   the Compulsory Acquisition or the requisition for hire (other than a
            requisition for hire for a temporary period not exceeding ninety
            (90) days) of the Rig; or

      (d)   the hijacking, theft, seizure, detention or disappearance of the Rig
            resulting in loss of possession by the person authorised to have
            possession of it for a period of ninety (90) days or longer;

      "TOTAL LOSS DATE" means the date upon which the Rig is deemed to have
      become a Total Loss pursuant to Clause 11.2 (c);

      "TOTAL LOSS PAYMENT DATE" means the earliest of any of the following dates
      next occurring after the Total Loss Date:

      (a)   the date falling one hundred and eighty (180) days after the Total
            Loss Date (or such later day as the Sub-Lessor may agree from time
            to time); or

      (b)   the first Business Day after the day on which the Head-Lessor, the
            Sub-Lessee or any other person receives the Total Loss Proceeds or
            Requisition Compensation;

      "TOTAL LOSS PROCEEDS" means the proceeds of any policy or contract of
      insurance arising in respect of a Total Loss;

      "UKCS" means the United Kingdom Continental Shelf, being the area so
      described in the Continental Shelf (Designation of Areas) (Consolidation)
      Order 2000 and the Continental Shelf (Designation of Areas) Order 2001;

      "VAT IRRECOVERABLE ON SALE" means VAT incurred by the Lessor in connection
      with its sale of its interest as owner of the Rig and the Lessee's
      Interest which is irrecoverable owing in whole or in part to the nature of
      the service supplied by the Lessor in disposing of the Lessee's Interest;

      "VOLUNTARY TERMINATION" means termination of this Sub-Lease by the
      Sub-Lessee in accordance with Clause 13.5(Voluntary Termination);

      "VOLUNTARY TERMINATION NOTICE" has the meaning ascribed to it in Clause
      13.5.

1.2   CONSTRUCTION OF TERMS. CONSTRUCTION OF TERMS. In this Sub-Lease, unless
      the contrary intention appears, a reference to:

(a)   (i)   an "AMENDMENT" includes any supplement, novation or re-enactment
            and "amended" is to be construed accordingly;

            "ASSETS" includes present and future properties, revenues and rights
            of every description;

            "ASSIGNEE" or "ASSIGNS" of a person shall include any person who has
            assumed all or some of the rights and/or obligations of the relevant
            person, whether by assignment, novation or otherwise;


                                       10
<PAGE>

            "AUTHORISATION" includes any authorisation, consent, approval,
            resolution, licence, permit, exemption, filing and registration;

            "INCLUDING" and "IN PARTICULAR" shall be construed as being by way
            of illustration or emphasis only and shall not be construed as, nor
            shall they take effect as, limiting the generality of the foregoing
            words;

            "OTHER" and "OTHERWISE" shall not be construed ejusdem generis with
            any foregoing words where a wider construction is possible;

            a "PERSON" includes any individual, company, corporation, firm,
            association, trust, unincorporated organisation or body of persons
            (including a partnership, joint venture or consortium), government
            (including any agency, department or political sub-divisions
            thereof), state, agency, international organisation, European Union
            institution, committee, department or authority or other entity
            whether having distinct legal personality or not or any association
            or partnership of two or more of the foregoing and its successors
            (whether of the same name or another name) and permitted assignees;

            a "REGULATION" includes any regulation, rule, official directive,
            request or guideline (whether or not having the force of law) of any
            governmental, inter-governmental or supranational body, agency,
            department or regulatory, self-regulatory or other authority or
            organisation;

            "WINDING-UP" of a person also includes the amalgamation,
            reconstruction, re-organisation, administration, dissolution,
            liquidation, merger or consolidation of that person, and any
            equivalent or analogous procedure under the law of any jurisdiction
            in which that person is incorporated, domiciled or resident or
            carries on its business or has assets;

      (ii)  in this Sub-Lease, unless the contrary intention appears, a
            provision of law is a reference to that provision as amended or
            re-enacted;

      (iii) in this Sub-Lease reference to a Clause, a paragraph, a
            sub-paragraph, or a Schedule is, unless specified a reference to a
            clause, a paragraph, a sub-paragraph of or a schedule to this
            Sub-Lease as from time to time amended in accordance with the
            provisions of this Sub-Lease;

      (iv)  a Lease Document or another document is a reference to that Lease
            Document or other document as amended or substituted from time to
            time;

(b)   the index to and headings in this Sub-Lease are for convenience only and
      are to be ignored in construing this Sub-Lease; and

(c)   in this Sub-Lease words importing the singular shall include the plural
      and vice versa.

1.3   If the Sub-Lessor considers that an amount paid by the Sub-Lessee under a
      Lease Document is capable of being avoided or otherwise set aside on the
      liquidation or administration of the Sub-Lessee, then that amount shall
      not be considered to have been irrevocably paid for the purposes of the
      Lease Documents.

2     LEASING OF THE RIG

2.1   QUIET ENJOYMENT. Subject to and in accordance with the terms of this
      Sub-Lease and subject to the due performance by the Sub-Lessee of its
      obligations under this Sub-Lease and the other Lease Documents to which it
      is a party, the Sub-Lessor irrevocably warrants and undertakes that
      provided that:


                                       11
<PAGE>

(a)   the Sub-Lessor has no right to terminate the leasing of the Rig under this
      Sub-Lease; and

(b)   the Head-Lessor continues to make the Rig available to the Sub-Lessor in
      accordance with the Head-Lease,

      the Sub-Lessee will, throughout the Sub-Lease Period, be entitled
      peaceably to hold and use the Rig without interference from the Sub-Lessor
      or any person acting through the Sub-Lessor subject to the rights of the
      Charterer under the Charter and the rights of the Operator.

2.2   AGREEMENT TO LEASE. Subject to and in accordance with the terms of this
      Sub-Lease, the Sub-Lessor agrees to let the Rig to the Sub-Lessee and the
      Sub-Lessee agrees to take the Rig on lease from the Sub-Lessor for the
      Sub-Lease Period. The sub-lease of the Rig is subject to the Charter and
      to the Service Contract and to the rights of the Charterer and the
      Operator.

3     COMMENCEMENT OF SUB-LEASE PERIOD

3.1   COMMENCEMENT OF SUB-LEASE PERIOD. The Sub-Lease Period shall commence
      immediately following the commencement of the Lease Period under the
      Head-Lease.

3.2   DELIVERY. Delivery of the Rig by the Sub-Lessor to the Sub-Lessee under
      this Sub-Lease and acceptance thereof by the Sub-Lessee shall, without any
      action on the part of the Sub-Lessor, be deemed to take place immediately
      upon commencement of the Sub-Lease Period.

3.3   CERTIFICATE OF ACCEPTANCE. Immediately following the commencement of the
      Sub-Lease Period, the Sub-Lessor and the Sub-Lessee will both execute the
      Certificate of Acceptance. Execution of the Certificate of Acceptance by
      the Sub-Lessor and the Sub-Lessee shall without further act be irrevocable
      evidence that the Sub-Lessee:

(a)   has found the Rig to be complete, in good order and condition, of
      satisfactory quality, fit for any purpose for which it is intended or
      required and in every way satisfactory; and

(b)   has accepted delivery of and has irrevocably and unconditionally accepted
      the Rig.

4     RENTALS

4.1   The Sub-Lessee shall throughout the Sub-Lease Period, without demand, pay
      to the Sub-Lessor the five instalments of Rental on the appropriate Rental
      Payment Date.

5     PAYMENTS

5.1   PAYMENTS. Wherever in this Sub-Lease provision is made for the payment by
      one party to another, such payment will be effected by crediting the
      account specified in the Payment Account Details of the party entitled to
      payment in immediately available cleared funds on or before the due date
      for payment. All payments shall be made without any set-off, counterclaim
      deduction or withholding (subject to the provisions of Clause 6
      (Withholding)). All payments by the Sub-Lessee to the Sub-Lessor in
      accordance with this Agreement shall be made from an account in the United
      Kingdom.

5.2   INTEREST ON OVERDUE AMOUNTS. If any payment due from the Sub-Lessee to the
      Sub-Lessor under this Sub-Lease is not paid on the due date, or if the
      Sub-Lessor makes any payment under the powers conferred on it, the
      Sub-Lessee shall, without prejudice to the Sub-Lessor's other rights and
      remedies, pay on demand interest thereon at the Default


                                       12
<PAGE>

      Rate (as well after as before judgment) from and including such due date,
      or the date of payment by the Sub-Lessor, to, but excluding, the date of
      actual payment. Such interest shall accrue on a daily basis, assuming a
      year of three hundred and sixty (360) days, and be compounded monthly.

5.3   BUSINESS DAYS. If a payment under this Sub-Lease is due on a day which is
      not a Business Day, the due date for that payment shall instead be the
      next Business Day in the same calendar month (if there is one) or the
      preceding Business Day (if there is not).

5.4   VAT. All payments due to the Sub-Lessor under this Sub-Lease are
      calculated without regard to VAT which, if applicable, will be added at
      the appropriate rate. If any VAT is due, the Sub-Lessee shall pay to the
      Sub-Lessor such VAT together with any interest and penalties thereon on
      demand by the Sub-Lessor, such demand to be made no earlier than such date
      as shall be reasonably necessary to enable the VAT to be paid on the last
      date for the payment of such VAT to avoid incurring interest and
      penalties. The Sub-Lessor shall promptly provide the Sub-Lessee with a
      valid VAT invoice in respect of each supply made under this Sub-Lease by
      the Sub-Lessor and such invoice shall comply with all relevant laws and
      regulations relating to VAT (including, in particular, Part III of the
      Value Added Tax Regulations 1995 (as amended)).

5.5   INCORRECT VAT. If the Sub-Lessee pays the Sub-Lessor an amount in respect
      of VAT under Clause 5.4 (VAT) and HM Customs and Excise ("CUSTOMS") rules
      that all or part of it was not properly chargeable (an "INCORRECT VAT
      CHARGE") the party receiving the ruling shall immediately notify the other
      of it and, the Sub-Lessor shall pay to the Sub-Lessee no later than five
      (5) Business Days after such notification an amount equal to that
      incorrect VAT charge together with any interest paid by Customs in respect
      of such Incorrect VAT Charge.

5.6   AMOUNTS PAYABLE BY SUB-LESSEE. All amounts payable by the Sub-Lessee under
      this Lease by way of indemnity or reimbursement of any Losses, Taxes and
      the like incurred or suffered by any Indemnified Person are payable in the
      currency in which the Loss, Tax or other like amount was incurred or
      suffered.

5.7   CURRENCY. All other amounts payable under this Lease are, except as
      otherwise provided in this Lease, payable in Dollars and shall be made for
      value on the due date.

5.8   TIME OF THE ESSENCE. Punctual payment of amounts due from the Sub-Lessee
      and timely performance by the Sub-Lessee of each of its obligations under
      this Sub-Lease shall, subject to any time periods specified in paragraph
      (a) or (c) of Clause 13.1 (Termination Events) be of the essence and are
      conditions of this Sub-Lease.

5.9   PAYMENTS UNCONDITIONAL. The Sub-Lessee's obligation to pay Rentals and
      make other payments, and perform any obligations owed to the Sub-Lessor
      pursuant to or in connection with this Sub-Lease shall be absolute and
      unconditional and shall not be affected by and shall be irrespective of
      any contingency whatsoever including (but not limited to):

(a)   any right of set-off, counterclaim, recoupment, defence, deduction or
      other right;

(b)   any unavailability of the Rig for any reason, including, but not limited
      to, requisition thereof, or any prohibition or interruption of or other
      restriction against the Sub-Lessor's, the Sub-Lessee's, the Charterer's or
      any other person's use, operation or possession of the Rig, any
      interference with such use, operation or possession or failure to deliver
      any part of the Rig or any lack or invalidity of title or any other defect
      in the title, suitability, seaworthiness, satisfactory quality,
      merchantability, fitness for any purpose, condition, appearance, safety,
      design, or operation of any kind or nature of the Rig, or the


                                       13
<PAGE>

      ineligibility of the Rig for any particular use or trade, or for want of
      registration or the absence or withdrawal of any permit, licence,
      authorisation or other documentation required under the applicable law of
      any relevant jurisdiction for the ownership, leasing, use, operation or
      location of the Rig, or (subject to Clause 11.3 (Confirmation of Sub-Lease
      Period)) the Total Loss of, or any damage to, the Rig or any part thereof;

(c)   any insolvency, bankruptcy, winding-up, administration, reorganisation,
      reconstruction, arrangement, readjustment or rescheduling of debt,
      dissolution, liquidation or similar proceedings by or against the
      Sub-Lessor, the Sub-Lessee, the Guarantor, the Sub-Lessor Parent or any
      other person (whether a party to any Lease Document or not);

(d)   any validity or unenforceability or lack of due authorisation of, or other
      defect in, this Sub-Lease or any of the other Lease Documents or any
      particular provision hereof or thereof;

(e)   any failure or delay on the part of any party, whether with or without
      fault on its part, duly to perform or comply with its obligations under
      this Sub-Lease or any of the other Lease Documents; and

(f)   any other case which but for this provision would or might have the effect
      of terminating or in any way affecting any obligation of the Sub-Lessee
      hereunder,

      (but without prejudice to the rights of the Sub-Lessee to damages or
      specific performance or any other injunctive relief in respect of this
      Sub-Lease or any of the other Lease Documents).

6     WITHHOLDING

6.1   PAYMENTS. All sums payable to the Sub-Lessor pursuant to or in connection
      with this Sub-Lease and any other Lease Document or any other document
      contemplated by or entered into pursuant to either the Sub-Lease or any
      other Lease Document as appropriate shall be paid free and clear of all
      deductions or withholdings whatsoever in respect of Taxes unless required
      by applicable law.

6.2   GROSS-UP. If the Sub-Lessee is required by applicable law to make a
      deduction or withholding in respect of Taxes from any amount due under
      this Sub-Lease the Sub-Lessee shall:

      (a)   ensure or procure that the deduction or withholding is made and that
            it does not exceed the minimum legal requirement therefor;

      (b)   pay, or procure the payment of the full amount deducted or withheld
            to the relevant Taxation or other authority in accordance with the
            applicable law;

      (c)   and such deduction or withholding arises as a result of (x) a Change
            of law, or (y) the Rig being or becoming a Fixture, increase the
            payment in respect of which the deduction or withholding is required
            so that the net amount received by the Sub-Lessor after the
            deduction or withholding (and after taking account of any further
            deduction or withholding which is required to be made which arises
            as a consequence of the increase) shall be equal to the amount which
            the Sub-Lessor would have been entitled to receive in the absence of
            any requirement to make a deduction or withholding; and

(d)   promptly deliver or procure the delivery to the Sub-Lessor of appropriate
      receipts evidencing the deduction or withholding which has been made;

      PROVIDED THAT if the Sub-Lessor determines, in its absolute discretion,
      that it has received, realised, utilised and retained a Tax benefit by
      reason of any deduction or withholding in


                                       14
<PAGE>

      respect of which the Sub-Lessee has made an increased payment under this
      Clause 6.2, the Sub-Lessor shall, provided it has received all amounts
      which are then due and payable by the Sub-Lessee under any of the
      provisions of this Sub-Lease, pay to the Sub-Lessee (to the extent that
      Sub-Lessor can do so without prejudicing the amount of that benefit and
      the right of the Sub-Lessor to obtain any other benefit, relief or
      allowance which may be available to it) such amount, if any, as the
      Sub-Lessor in its absolute discretion, shall determine will leave the
      Sub-Lessor in no better and no worse position than the Sub-Lessor would
      have been in if the deduction or withholding had not been required;

      PROVIDED FURTHER THAT:

      (i)   the Sub-Lessor shall have an absolute discretion as to the time at
            which and the order and manner in which it realises or utilises any
            Tax benefit;

      (ii)  the Sub-Lessor shall not be obliged to disclose any information
            regarding its business, Tax affairs or Tax computations or those of
            any member of the Sub-Lessor Group;

      (iii) if the Sub-Lessor has made a payment to the Sub-Lessee pursuant to
            this Clause 6.2 on account of any Tax benefit and it subsequently
            transpires that the Sub-Lessor did not receive that Tax benefit, or
            received a lesser Tax benefit, the Sub-Lessee shall pay on demand to
            the Sub-Lessor such sum as the Sub-Lessor may, in its absolute
            discretion, determine is necessary to restore the after-Tax position
            of the Sub-Lessor to that which it would have been had no adjustment
            under this proviso (iii) been necessary;

      (iv)  the Sub-Lessor shall not be obliged to make any payment under this
            Clause 6.2 if, by doing so, it would contravene the terms of any
            applicable law or any notice, direction or requirement of any
            governmental or regulatory authority (whether or not having the
            force of law),

6.3   TREATY RELIEF. If the Sub-Lessee requests the Sub-Lessor, in writing, to
      make an appropriate application in writing to an appropriate Tax authority
      pursuant to the provisions of a double tax treaty for relief (whether in
      whole or in part) in respect of any deduction or withholding on account of
      Taxes required by law, the Sub-Lessor shall, PROVIDED THAT the Sub-Lessor
      is indemnified to its satisfaction in respect of any costs, expenses,
      damages or claims it may incur or suffer in connection therewith, take
      such action as the Sub-Lessee shall reasonably request to make such
      application to an applicable Tax authority. The Sub-Lessor shall be under
      no obligation to appeal, contest or dispute any decision, ruling or
      determination by that Tax authority that the provisions of the double tax
      treaty in respect of which the application referred to in this Clause is
      made do not apply to the deduction or withholding on account of Taxes in
      respect of which that application is made. If the Sub-Lessor subsequently
      obtains a repayment (whether in whole or in part) of such deduction or
      withholding from that Tax authority in circumstances where Sub-Lessee has
      made an increased payment under Clause 6.2 the Sub-Lessor shall, provided
      that the Sub-Lessor has received all amounts which are then due and
      payable by the Sub-Lessee under any of the provision of this Sub-Lease pay
      to the Sub-Lessee such amount of the repayment as the Sub-Lessor
      considers, in its absolute discretion, will leave the Sub-Lessor in no
      worse position than the Sub-Lessor would have been in if the deduction or
      withholding had not been required.

7     LOCATION, USE AND MAINTENANCE OF RIG

7.1   LOCATION AND MOVEMENT OF THE RIG.

(a)   The Sub-Lessee will not move the Rig outside the UKCS (except as may be
      required for repair and maintenance) without the prior written consent of
      the Sub-Lessor, such consent


                                       15
<PAGE>

      not to be unreasonably withheld in the case of re-deployment of the Rig to
      another sector of the North Sea which (in respect of operational,
      environmental and pollution liabilities) the Sub-Lessor considers, acting
      reasonably, creates no materially greater risk of potential liability for
      the Sub-Lessor than that of the UKCS at the time of such proposed
      re-deployment.

(b)   Subject to Clause 7.1(a), the Sub-Lessee shall notify the Sub-Lessor at
      least thirty (30) days before moving the Rig from the territorial waters
      of UKCS (or from any other location to which the Rig may be moved
      following a notification to the Sub-Lessor pursuant to this Clause
      7.1(b)), such notification to specify the place to which the Rig is to be
      moved and the jurisdictions through which the Rig will pass in its
      proposed voyage.

(c)   On reasonable request from time to time, the Sub-Lessee shall provide
      written confirmation to the Sub-Lessor of the current location of the Rig.

7.2   MAINTENANCE. The Sub-Lessee shall throughout the Sub-Lease Period maintain
      the Rig in good working order and fit for the purpose for which it is
      employed and shall carry out all necessary maintenance and repair in
      accordance with the GSF Standard.

7.3   SAFETY AND OPERATION. The Sub-Lessee shall take such steps as are
      reasonably practicable to ensure that the Rig and all constituent parts
      thereof will be safe and without risk to health when in use and that the
      Rig is not operated beyond its specified or recommended limits or
      capacity. To this end and without prejudice to the generality of the
      foregoing, the Sub-Lessee shall ensure that any defects in the Rig which
      could be or cause a danger to safety and a risk to health are repaired and
      made good in accordance with the GSF Standard. For this purpose the
      Sub-Lessee shall cause the Rig to be inspected regularly and its various
      systems tested PROVIDED THAT such inspection and testing will only be
      carried out in accordance with and at the interval specified in the
      Sub-Lessee's maintenance schedule for the Rig and otherwise in accordance
      with the GSF Standard. The Sub-Lessee shall also take all steps to ensure
      that appropriate safety measures are adopted and all provisions of all
      applicable laws, codes and regulations relating to the Rig are complied
      with.

7.4   AUTHORISATIONS. The Sub-Lessee shall obtain and keep in full force and
      effect throughout the Sub-Lease Period, at no cost to the Sub-Lessor, all
      permissions, licences and other authorisations which may from time to time
      be required in connection with the ownership, possession, use or operation
      of the Rig.

7.5   COSTS AND EXPENSES. the Sub-Lessee will ensure that throughout the
      Sub-Lease Period and subject to Clause 8.4 (Notification), all debts,
      costs, expenses, losses, liabilities, premiums, calls, contributions,
      penalties, charges, fines, recourses, duties, Taxes, rents, rates, and
      registration charges and other outgoings which during the Sub-Lease Period
      give or may give rise to any Encumbrance (other than any Permitted
      Encumbrances) are promptly paid in full in relation to the Rig.

7.6   MANAGEMENT OF THE RIG. The Rig will at all times be managed in accordance
      with the GSF Standard.

7.7   ENVIRONMENTAL LAWS. The Sub-Lessee will and will procure that the Operator
      will:

(a)   comply with all Environmental Laws which are applicable to the Rig,
      (including, without limitation, obtaining, complying with and maintaining
      in full force and effect all Environmental Permits required from time to
      time and all requirements relating to manning, submission of oil spill
      response plans and designation of qualified individuals) which might
      reasonably be expected to, or failure to comply with or maintain might,
      have a material adverse effect on the rights or interests of the
      Sub-Lessor (it being acknowledged that without prejudice to the generality
      of the foregoing, if the same would


                                       16
<PAGE>

      involve the Sub-Lessor in any material civil liability or any criminal
      liability, then the same shall be deemed to materially and adversely
      affect the rights and interests of the Sub-Lessor) or on the ability of
      the Sub-Lessee to fulfil its obligations under the Lease Documents;

(b)   conduct and complete all reasonably necessary investigations, studies,
      sampling, audits and testings required in connection with any known (or
      threatened) material Release of Hazardous Materials; and

(c)   promptly upon the occurrence of any of the following events, provide to
      the Sub-Lessor a certificate specifying in detail the nature of the event
      concerned:

      (i)   the receipt of any Environmental Claim (made or threatened) against
            the Rig, the Sub-Lessor, the Sub-Lessee or the Operator or which is
            in relation to or is caused by or is in connection with the Rig and
            which the Lessee is obliged under any applicable law to report to
            any Governmental Entity; and

      (ii)  any revocation, suspension, amendment, variation, withdrawal or
            refusal to grant any Environmental Permit or any requirement
            relating to manning, submission of oil response plans and
            designation of qualified individuals; or

      (iii) any (or any threatened) material release of Hazardous Materials,

      which might reasonably be expected to have a material adverse effect of
      the nature referred to in paragraph (a) above.

7.8   OBSTRUCTION. The Sub-Lessee shall pay all charges and expenses of every
      kind and nature whatsoever incidental to the use and operation of the Rig
      and, if the Rig or any part thereof becomes a wreck or an obstruction to
      navigation, any costs and expenses arising which may be incurred by or
      made or asserted against the Sub-Lessor in connection with or as a
      consequence of the removal or destruction of the wreck or obstruction. The
      Sub-Lessee shall be entitled to take action to contest or avoid any
      charges or expenses subject to and in accordance with Clause 14.4 (Defence
      of Claims), mutatis mutandis.

7.9   PERFORMANCE. For as long as the Rig is subject to the Charter or
      thereafter sub-chartered to any member of the Guarantor's Group, the
      Sub-Lessee will procure that the Charterer or any future sub-charterer, as
      the case may be, will perform the obligations of the Sub-Lessee under this
      Sub-Lease which relates to operational, maintenance and management issues.
      Such performance will constitute pro tanto satisfaction of the
      Sub-Lessee's obligations under this Sub-Lease. For the avoidance of doubt,
      this Clause 7.9 shall not operate to waive or impair any obligation of the
      Sub-Lessee under this Sub-Lease, which shall continue in full force and
      effect.

7.10  COMPLIANCE WITH LAWS.  The Sub-Lessee will:

(a)   ensure that the Rig is used solely in the conduct of its or the Operator's
      business in compliance with all applicable laws, treaties or conventions
      (and all rules and regulations issued thereunder), including but not
      limited to the ISM Code to the extent applicable and all Environmental
      Laws ("APPLICABLE LAWS") and will ensure that the Rig complies with all
      Applicable Laws; and

(b)   not cause or permit the Rig to be:

      (i)   operated in any manner contrary to any Applicable Law; or

      (ii)  employed in any trade or business which is unlawful under any
            Applicable Law.

7.11  ACCOUNTS AND FINANCIAL INFORMATION. The Sub-Lessee shall provide to the
      Sub-Lessor:


                                       17
<PAGE>

(a)   a copy of its annual audited accounts for each of its financial years; and

(b)   (or, as the case may be, shall procure that there is provided to the
      Sub-Lessor) such reasonably available financial information relating to
      the Sub-Lessee as the Sub-Lessor may reasonably request from time to time.

7.12  SUB-CHARTERING.

(a)   The Sub-Lessee shall be entitled to sub-lease or sub-charter the Rig to
      any person or otherwise employ the Rig without the prior consent of the
      Sub-Lessor.

(b)   The sub-leasing, sub-chartering or other employment of the Rig by the
      Sub-Lessee to any person will not in any way release the Sub-Lessee from
      its obligations under this Agreement or the other Lease Documents.

8     PROTECTION OF THE SUB-LESSOR'S INTERESTS

8.1   NO AUTHORITY TO CREATE ENCUMBRANCES. The Sub-Lessee will not and will
      procure that each of the Charterer and any other Operator will not:

(a)   pledge the credit of the Sub-Lessor or any member of the Sub-Lessor Group
      for the repair of the Rig or otherwise;

(b)   create, purport to create or, subject to Clause 8.2 (Arrest or Detention),
      permit to subsist any Encumbrance on, over or with respect to the Rig
      (other than Permitted Encumbrances);

(c)   sell, attempt to sell or, otherwise dispose of, the Rig or any interest
      therein, or purport so to do without the previous written consent of the
      Sub-Lessor or unless the requirements of Clause 22.2 are satisfied; or

(d)   part with possession of the Rig other than in accordance with Clause 7.12
      (Sub-chartering) and except as may be required for repair and maintenance.

8.2   ARREST AND DETENTION. If the Rig is at any time during the Sub-Lease
      Period:

(a)   arrested, seized, taken into custody or otherwise detained by any person
      or by any court or other tribunal or by any Governmental Entity (other
      than by a Compulsory Acquisition or any requisition for hire or by reason
      of a Sub-Lessor's Encumbrance); or

(b)   subjected to distress or other legal proceedings by reason of any process,
      claim, the exercise of any rights conferred by an Encumbrance or by any
      other action whatsoever (other than by reason of a Sub-Lessor's
      Encumbrance),

      the Sub-Lessee shall procure the release of the Rig from such arrest,
      seizure or detention within twenty-one (21) days of receiving notice
      thereof by providing bail or otherwise as the circumstances may require.
      The Sub-Lessor acknowledges and accepts that the Sub-Lessee shall, unless
      and until a Termination Event shall have occurred which is continuing,
      have the sole right to contest any litigation, arbitration or
      administrative proceedings in respect of the foregoing subject to and in
      accordance with Clause 14.4 (Defence of Claims), mutatis mutandis.

8.3   INFORMATION CONCERNING THE RIG. The Sub-Lessee undertakes with the
      Sub-Lessor that, from the Start Date and throughout the Sub-Lease Period
      it will promptly furnish the Sub-Lessor with all such information as the
      Sub-Lessor may from time to time reasonably request in writing regarding
      the Rig, its insurance, condition, maintenance, position and employment.


                                       18
<PAGE>

8.4   NOTIFICATION. The Sub-Lessee shall notify the Sub-Lessor in writing
      promptly at the Sub-Lessee's cost and expense of:

(a)   any occurrence in consequence whereof the Rig has become or is, in the
      reasonable opinion of the Sub-Lessee, likely to become a Total Loss;

(b)   any material assistance which has been given to the Rig which has resulted
      or may result in a lien for salvage being acquired over the Rig;

(c)   the requisition for hire, requisition for title, sequestration,
      forfeiture, any Compulsory Acquisition whatsoever, hijacking, theft,
      seizure or detention at any time of the Rig; and

(d)   any event which occurs in connection with the Rig which, in the reasonable
      opinion of the Sub-Lessee, affects or might affect the rights of the
      Sub-Lessor in the Rig or involves or might involve any material loss or
      liability to or of the Sub-Lessor.

8.5   NOTICE OF LEASE. The Sub-Lessee shall place and keep or procure that there
      is placed and kept prominently displayed in the control room of the Rig
      throughout the Sub-Lease Period a framed printed notice in plain type in
      English of such size that the paragraph of reading matter shall cover a
      space of not less than six (6) inches wide by nine (9) inches high,
      reading substantially as follows:

      "NOTICE OF LEASE"

      "This Rig is the property of GlobalSantaFe Drilling Company (North Sea)
      Limited (in such capacity, the "LESSOR") and is subject to a head lease
      granted by the Lessor to Sogelease B.V. (the "LESSEE"). This Rig is
      subject to a sub-lease granted by the Lessee to GlobalSantaFe Drilling
      Company (North Sea) Limited (in such capacity, the "SUB-LESSEE").

      Neither the Lessor, the Sub-Lessee, nor any manager, nor any servant or
      agent of them has any authority whatsoever to contract on behalf of the
      Lessee or to pledge the credit of the Lessee or the involvement of the
      Lessee in any liability whatsoever.

      Under the terms of the Head-Lease and the Sub-Lease the Lessee has no
      operational responsibility for the Rig."

      The Sub-Lessee undertakes not to remove or cover up that notice.

8.6   PRIORITY. The Sub-Lessee hereby covenants that it will procure that its
      obligations under the Lease Documents will rank at least pari passu with
      its other present and future unsecured and unsubordinated obligations,
      except for those obligations which are mandatorily preferred by law in
      England.

8.7   NOTIFICATION OF TERMINATION EVENT. The Sub-Lessee undertakes with the
      Sub-Lessor that, from the date of this Sub-Lease and throughout the
      Sub-Lease Period, to promptly notify the Sub-Lessor of the occurrence of
      any Termination Event or any event which would with the lapse of time or
      giving of any notice result in a Termination Event promptly upon becoming
      aware thereof.

8.8   SUB-LESSOR'S ENCUMBRANCES. The Sub-Lessor will not create or, subject to
      Clause 8.9 (Arrest following a Sub-Lessor's Encumbrance) purport to create
      or permit to subsist any Sub-Lessor's Encumbrances on, or over or with
      respect to the Rig.

8.9   ARREST FOLLOWING A SUB-LESSOR'S ENCUMBRANCE. If the Rig is at any time
      during the Sub-Lease Period:


                                       19
<PAGE>

(a)   arrested, seized, taken into custody or otherwise detained by any person
      or by any court or other tribunal or by any Governmental Entity by reason
      of a Sub-Lessor's Encumbrance; or

(b)   subjected to distress or other legal proceedings by reason of any process,
      claim, the exercise of any rights conferred by a Sub-Lessor's Encumbrance,

      the Sub-Lessor shall procure the release of the Rig from such arrest,
      seizure or detention within twenty-one (21) days of receiving notice
      thereof by providing bail or otherwise as the circumstances may required.

9     EXCLUSION OF LIABILITY

9.1   NO REPRESENTATION IN RESPECT OF THE RIG. It is expressly agreed and
      acknowledged that no term, condition, warranty or representation of any
      kind whatsoever (express or implied) is or has been given by or on behalf
      of the Sub-Lessor in respect of the Rig (or any part thereof). All terms,
      conditions, warranties and representations (express or implied and whether
      statutory, collateral hereto or otherwise) relating to the Rig, its title
      specification, age, quality, description, seaworthiness, satisfactory
      quality or as to its fitness for any purpose are, to the extent permitted
      by applicable law, hereby expressly excluded and the Sub-Lessee
      acknowledges that it is sub-leasing the Rig on an "as is where is" basis
      and the Sub-Lessee has been solely responsible for selecting the Rig and
      agreeing the specification of the Rig with the manufacturer or supplier
      relying on its own skill and judgment.

9.2   NO AGENCY. The Sub-Lessee acknowledges that no person not actually in the
      employ of the Sub-Lessor is or is deemed to be the agent or entitled to
      act on behalf of, or make any representation or warranty binding on, the
      Sub-Lessor.

9.3   NO LIABILITY FOR LOSS. The Sub-Lessor shall not be liable (in contract,
      tort or otherwise) for any claim, damage, liability, or loss (including
      consequential loss) or expense of any kind arising directly or indirectly
      in connection with the Rig (or any part thereof) or from any delay in
      delivery of or failure to deliver the Rig, any defect or deficiency in, or
      inadequacy or unsuitability of, the Rig (or any part thereof) or its use,
      performance, servicing or repair; PROVIDED THAT nothing contained herein
      shall exclude any liability of the Sub-Lessor:

(a)   in respect of any claim, damage, liability or loss arising solely as a
      result of the negligence or wilful misconduct of the Sub-Lessor; or

(b)   for death or personal injury caused by the Sub-Lessor's negligence to the
      extent that such exclusion is prohibited by statute.

9.4   NO OBLIGATION TO REPLACE. The Sub-Lessor shall have no obligation to
      supply to the Sub-Lessee any replacement for the Rig (or any part thereof)
      if the same is, either on delivery or thereafter defective, lost, damaged,
      unusable or unavailable for any reason and the Sub-Lessee shall not (other
      than by the express terms of this Sub-Lease) be entitled to any remission
      of, or be released from any obligation to pay, Rentals or any other
      payments hereunder by reason thereof.

9.5   REASONABLENESS OF TERMS. The Sub-Lessor and the Sub-Lessee acknowledge
      that they have each carefully considered this Clause 9 (Exclusion of
      Liability) and the exclusions and limitations contained within it and the
      Sub-Lessee agrees that the limitations on liability and exclusions of
      liability set out in this Clause 9 (Exclusion of Liability) are


                                       20
<PAGE>

      reasonable having regard to the terms and conditions of this Sub-Lease
      generally and the transactions contemplated by the Lease Documents as a
      whole.

10    INSURANCE

10.1  INSURANCES IN RESPECT OF THE RIG. The Sub-Lessee will throughout the
      Sub-Lease Period:

(a)   insure and keep the Rig insured free of cost and expense to the Sub-Lessor
      against protection and indemnity risks (including oil pollution liability)
      on terms and conditions taking into account customary insurance market
      practice taken out for offshore rigs of the same type, size and age as the
      Rig and otherwise in accordance with the practice from time to time of
      prudent owners of similar types of offshore rigs as the Rig for an
      aggregate limit of cover of not less than two hundred million Dollars
      (US$200,000,000) per occurrence;

(b)   effect the Required Insurances with reputable insurance companies or
      underwriters or mutual insurance associations or clubs as the Sub-Lessor
      shall from time to time approve in writing such approval not to be
      unreasonably withheld or delayed;

(c)   each policy or entry maintained by the Sub-Lessee in accordance with the
      provisions of Clause 10.1(a) shall:

      (i)   contain an endorsement reflecting the interest of the Sub-Lessor in
            the Rig or otherwise cover the Sub-Lessor in respect of claims which
            may be forthcoming thereunder; and

      (ii)  be in the name of the Sub-Lessee and shall further name the
            Sub-Lessor as additional assured save that it shall provide that the
            Sub-Lessor shall not be liable for any premiums, calls,
            contributions or other sums payable in respect of each such policy;

(d)   punctually pay all premiums, calls, contributions or other sums payable in
      respect of the Required Insurances;

(e)   notify the Sub-Lessor at least fourteen days before the relevant policies,
      contracts or entries expire and confirm in writing to the Sub-Lessor as
      and when renewals of insurances complying with Clause 10.1(a) have been
      effected;

(f)   arrange for the execution and delivery of such guarantees or indemnities
      as may from time to time be required by any protection and indemnity
      association;

(g)   procure that any insurance company, mutual insurance association or club
      with whom the Required Insurances are placed shall furnish the Sub-Lessor
      with a copy of the certificate of entry and a letter or letters of
      undertaking in such form as shall from time to time be reasonably required
      by the Sub-Lessor having regard to current market practice at the time of
      issue of any such letter of undertaking;

(h)   provide the Sub-Lessor, promptly upon request by the Sub-Lessor of the
      same, with copies of all certificates of insurances or entries issued by
      the relevant insurers evidencing that the insurances have been effected by
      the Sub-Lessee in compliance with this Clause 10;

(i)   advise the Sub-Lessor promptly of any material alterations to any Required
      Insurances that would or might affect the Sub-Lessor or any Indemnified
      Person and any act, omission or event of which the Sub-Lessee has
      knowledge which would or might render invalid or unenforceable any of the
      Required Insurances in whole or in part (including, without any
      limitation, any cancellation of any Required Insurances);


                                       21
<PAGE>

(j)   take all necessary action and comply with all requirements which may from
      time to time be applicable to the Required Insurances (including, without
      limitation, the making of all requisite declarations within any prescribed
      time limits and the payment of any additional premiums or calls) so as to
      ensure that the Required Insurances are not made subject to any exclusions
      or qualifications to which the Sub-Lessor has not given its prior written
      consent and are otherwise maintained on terms and conditions from time to
      time approved in writing by the Sub-Lessor (acting reasonably);

(k)   comply with the terms and conditions of the Required Insurances, not do,
      consent to or permit any act or omission which might invalidate or render
      unenforceable the whole or any part of the Required Insurances and not
      (without first obtaining the consent of the insurers to such employment
      and complying with such requirements as to extra premium or otherwise as
      the insurers may prescribe) employ the Rig or permit the Rig to be
      employed otherwise than in conformity with the terms of the insurances;

(l)   where it is a requirement of any applicable law or of the Required
      Insurances that any declarations are made or any certificates, returns or
      forms filed with any Governmental Entity or any of the insurers for the
      Rig from time to time in connection with the location or operation of the
      Rig in the territorial waters of, any country or state, promptly (and
      within any applicable time limits) complete and submit to the relevant
      Governmental Entity or, as the case may be, the relevant insurers all such
      declarations, certificates, returns and forms;

(m)   supply to the Sub-Lessor all necessary assistance which may be required by
      the Sub-Lessor in connection with making any claim under the Required
      Insurances; and

(n)   procure that the Required Insurances do not have an excess or deductible
      exceeding an amount which would be unacceptable to a reasonably prudent
      operator of rigs similar to the Rig, having regard to the insurance market
      conditions from time to time and any insurer will provide an annual
      certificate that in their opinion the level of deductible on the Required
      Insurances is consistent with that which is being obtained by
      owners/operators of other rigs similar to the Rig (having regard to the
      insurance market conditions at the time of the relevant certificate; and

(o)   not, without the prior written consent of the Sub-Lessor, take out
      additional insurances for the Sub-Lessee's sole benefit, or permit the
      Sub-Lessee or the Sub-Lessor to be named insured in insurances with
      respect to the Rig, other than as required under this Sub-Lease, where
      such additional insurances will or may prejudice the Required Insurances
      or recovery thereunder or will exceed the amount permitted by the
      warranties or other conditions of the Required Insurances (unless the
      insurers under the Required Insurances have consented thereto).

10.2  THIRD PARTY CLAIMS. Any insurance moneys paid under the Required
      Insurances shall be paid to the person to whom the liability (or alleged
      liability) covered by such insurances or entry was incurred or, if the
      liability (or alleged liability) to such person has previously been
      discharged by the Sub-Lessee such moneys shall be paid to the Sub-Lessee
      in reimbursement of the moneys so expended by it in satisfaction of such
      liability or alleged liability and, in such case, the Sub-Lessor shall pay
      any insurance moneys received by it in respect of such liability or
      alleged liability to the Sub-Lessee upon the Sub-Lessee furnishing
      evidence to the Sub-Lessor that such liability or alleged liability has
      previously been discharged.

10.3  APPLICATION OF OTHER INSURANCE PROCEEDS. Insurance payments which arise
      from any policy of insurance carried by the Sub-Lessee or any requisition
      or other compensation in place of such insurance payments, other than the
      Required Insurances, shall be paid to the Sub-Lessee; the Sub-Lessor shall
      have no right or interest in or in respect of such insurance policies or
      the proceeds thereof.


                                       22
<PAGE>

11    LOSS, DAMAGE AND REQUISITION

11.1  RISK. The Rig shall throughout the Sub-Lease Period be in every respect at
      the risk of the Sub-Lessee who shall bear all risks howsoever arising
      whether of navigation, operation and maintenance of the Rig or otherwise
      and, subject to Clause 2.1 (Quiet Enjoyment), of any other occurrence of
      whatever kind which shall deprive the Sub-Lessee of the use, possession or
      enjoyment thereof.

11.2  TOTAL LOSS.

(a)   In the event of a Total Loss of the Rig, the Sub-Lease Period and the
      Sub-Lessee's obligation to pay future Rentals under this Sub-Lease, save
      as otherwise provided in this Sub-Lease shall cease on the Total Loss
      Payment Date (without prejudice to the obligations of the Sub-Lessee to
      pay to the Sub-Lessor all sums which are then due and unpaid or which may
      become due or be ascertained under any paragraph of the Financial
      Schedule) and the Sub-Lessee shall on the Total Loss Payment Date pay to
      the Sub-Lessor an amount as rental which is the aggregate of the
      Termination Sum for the Total Loss Payment Date and all other moneys due
      and payable by the Sub-Lessee under the terms of this Sub-Lease.

(b)   The foregoing obligations of the Sub-Lessee shall apply even if moneys are
      not payable or have not been received under the insurances, even if the
      said compensation is not payable or have not been received and regardless
      of the cause of the Total Loss.

(c)   For the purposes of this Sub-Lease, a Total Loss shall be deemed to have
      occurred:

      (i)   in the case of an actual total loss of the Rig, at noon (London
            time) on the actual date and at the time the Rig was lost or, if
            such date is not known, on the day on which the Rig was last
            reported;

      (ii)  in the case of a constructive total loss of the Rig, upon the date
            and at the time notice of abandonment of the Rig is given to the
            insurers of the Rig for the time being (provided a claim for such
            constructive total loss is admitted by the insurers) or, if the
            insurers do not admit such a claim, at the date and at the time at
            which a constructive total loss is subsequently adjudged by a
            competent court of law to have occurred;

      (iii) in the case of a compromised or arranged total loss, on the date
            upon which a binding agreement as to such compromised or arranged
            total loss has been entered into by the insurers of the Rig;

      (iv)  in the case of Compulsory Acquisition, on the date upon which the
            relevant requisition of title or other compulsory acquisition
            occurs; and

      (v)   in the case of hijacking, theft, condemnation, confiscation,
            capture, detention, seizure of the Rig (other than where the same
            amounts to Compulsory Acquisition of the Rig) by any Governmental
            Entity, or by persons purporting to act on behalf of any
            Governmental Entity, which deprives the Sub-Lessee of the use of the
            Rig for more than one hundred and eighty (180) days, upon the expiry
            of the period of one hundred and eighty (180) days after the date
            upon which the relevant hijacking, theft, condemnation,
            confiscation, capture, detention or seizure occurred.

11.3  CONTINUATION OF SUB-LEASE PERIOD. The Sub-Lessee shall continue to pay
      Rental on the days and in the amounts required under this Lease
      notwithstanding that the Rig shall become a Total Loss, or if for any
      reason the Sub-Lessee shall be permanently deprived of her use prior to
      the end of the Sub-Lease Period, PROVIDED ALWAYS THAT no further
      instalments of Rental shall become due and payable after the date on which
      all sums due


                                       23
<PAGE>

      under Clause 11.2(a) shall have been paid in full and the Sub-Lease Period
      shall terminate on the date of such final payment.

11.4  APPLICATION OF REQUISITION COMPENSATION. In the event of the Compulsory
      Acquisition of the Rig, any Requisition Compensation received by the
      Sub-Lessor shall be paid to the Sub-Lessee.

11.5  NOTICE OF ABANDONMENT.

(a)   The Sub-Lessee shall have the sole right to determine whether or not a
      case has arisen for the giving of notice of abandonment to abandon the Rig
      to the insurers and/or claim a constructive total loss and the Sub-Lessee
      is hereby irrevocably authorised by the Sub-Lessor to give the same if it
      so determines.

(b)   The Sub-Lessor shall upon the request of the Sub-Lessee promptly execute
      such documents as may be required to enable the Sub-Lessee to abandon the
      Rig to the insurers and/or claim a constructive total loss and the
      Sub-Lessor shall give the Sub-Lessee all reasonable assistance within its
      power in pursuing the said claim. The Sub-Lessee shall indemnify and hold
      harmless the Sub-Lessor in respect of all Losses, costs and expenses
      incurred by the Sub-Lessor pursuant to this Clause 11.5 (b).

11.6  REQUISITION FOR HIRE

(a)   If the Rig is requisitioned for hire by any Governmental Entity during the
      Sub-Lease Period then, unless and until the Rig becomes a Total Loss
      following such requisition and the Sub-Lessee shall have made payment of
      all sums due pursuant to Clause 11.2 (Total Loss), the lease of the Rig to
      the Sub-Lessee under this Sub-Lease shall continue in full force and
      effect (subject always to the provisions of Clauses 11.2 (Total Loss) and
      13 (Termination)) for the remainder of the Lease Period and the Sub-Lessee
      shall remain fully responsible for the due compliance with all its
      obligations under this Sub-Lease other than such obligations which the
      Sub-Lessee is unable to comply with solely by virtue of such requisition.

(b)   The Sub-Lessee shall during the Sub-Lease Period be entitled to all
      requisition hire paid to the Sub-Lessor or the Sub-Lessee on account of
      such requisition and the Sub-Lessor shall account to the Sub-Lessee for
      any such requisition hire paid to it.

(c)   The Sub-Lessee shall, as soon as practicable after the end of any
      requisition for hire, which terminates before the expiry of the Sub-Lease
      Period, cause the Rig to be put into the condition required by this
      Sub-Lease, and where that requisition shall end after the expiry or
      termination of the Sub-Lease Period the Sub-Lessee shall, as soon as
      practicable, cause the Rig to be put into the re-delivery condition
      required by Clause 13.1(b), allowance being made for fair wear and tear in
      respect of the period from the expiry or termination of the Sub-Lease
      Period.

(d)   Should the Rig be under requisition for hire at the end of the Sub-Lease
      Period:

      (i)   the lease of the Rig under this Sub-Lease shall (unless otherwise
            agreed between the parties hereto) nevertheless be terminated at
            such end but without prejudice to the accrued rights of the parties
            and PROVIDED THAT no Termination Event shall have occurred and be
            continuing in which case the Sub-Lessor shall be entitled to retain
            the requisition hire to the extent of any payments that are then due
            and payable by the Sub-Lessee to the Sub-Lessor under this Sub-Lease
            and the Sub-Lessee's obligations to make such payments shall be pro
            tanto reduced by the amount of such retention and any remaining
            requisition hire shall be paid to the Sub-Lessee by way of rebate of
            Rental, the Sub-Lessee shall be entitled to receive and retain any
            requisition hire payable in respect of the period from the expiry of
            the Sub-Lease Period; and.


                                       24
<PAGE>

      (ii)  the Sub-Lessee shall, if and for so long as it is prevented by
            reason of the requisition hire from re-delivering the Rig under
            Clause 13.1 (Termination Events) be excused from its obligation to
            do so.

(e)   If the Rig is requisitioned for hire the Sub-Lessee hereby agrees to
      indemnify the Sub-Lessor against any Losses, costs and expenses incurred
      by the Sub-Lessor in connection with such requisition for hire.

12    RETURN AND SALE OF THE RIG

12.1  RE-DELIVERY OF THE RIG

(a)   On expiry or termination of the Sub-Lease Period (other than by reason of
      Total Loss) the Sub-Lessee shall redeliver the Rig to the Head-Lessor
      which redelivery shall be deemed to constitute redelivery to the
      Sub-Lessor under this Sub-Lease and the Sub-Lessor shall be deemed to have
      accepted such redelivery without further action on the part of either
      party.

(b)   The Rig when so re-delivered shall be:

      (i)   unless otherwise agreed by the Sub-Lessor in writing, in such state
            of repair and operating condition as it is required to be maintained
            in accordance with the provisions of this Sub-Lease, fair wear and
            tear and changes and alterations properly made by the Sub-Lessee as
            permitted under this Sub-Lease;

      (ii)  with all equipment, fittings, spare and replacement parts installed
            in or on, or which are attached to, or which are part of the Rig in
            accordance with this Sub-Lease which was entitled to be removed
            prior to re-delivery in accordance with Clause 14;

      (iii) with all required operating, safety and other certificates in full
            force and effect; and

      (iv)  free of all Encumbrances (other than Permitted Encumbrances).

12.2  SALE OF THE RIG

(a)   Where the Sub-Lease Period is to terminate in accordance with the
      provisions of this Sub-Lease on the Leasing Termination Date by reason of
      the service of a Termination Notice or a Voluntary Termination Notice the
      Sub-Lessor and the Sub-Lessee agree that they shall each offer for sale
      their respective interests in the Rig in accordance with this Clause 12.2.

(b)   Notwithstanding anything to the contrary contained elsewhere in this
      Sub-Lease the leasing of the Rig under this Sub-Lease shall continue until
      the earlier of (i) completion of a sale referred to in Clause 12.2(a),
      (ii) the date falling sixty (60) days after the Acceleration Date, (iii)
      the expiry of the Sub-Lease Period by effluxion of time, and (iv) the
      occurrence of a Total Loss Payment Date whereupon it shall terminate.

(c)   The Sub-Lessee shall be responsible for all costs and expenses incurred in
      connection with a sale of the respective interests of the Head-Lessor and
      the Sub-Lessor in the Rig.

12.3  SUB-LESSOR'S DISPOSAL PROCEEDS

(a)   The amount of the Sub-Lessor's Disposal Proceeds to which the Sub-Lessor
      is entitled under the terms of the Head-Lease following a sale of the Rig
      in accordance with the terms of the Head-Lease shall be applied as
      follows:


                                       25
<PAGE>

      (i)   first,to the extent than any payments are then due and payable by
            the Sub-Lessee to the Sub-Lessor under this Sub-Lease, to be
            retained (for the purpose of being applied in settlement of the
            Termination Sum or any other amounts so due and owing) by the
            Sub-Lessor to that extent and the Sub-Lessee's obligation to make
            such payments shall be pro tanto reduced by the amount of such
            retention; and

      (ii)  secondly, in retention by the Sub-Lessor of an amount equal to 0.1
            per cent. of the Net Sale Proceeds; and

      (iii) thirdly, the balance shall be paid (A) to the Sub-Lessee by way of
            rebate of Rentals or any other payments, including Termination Sum
            or any part thereof, paid by the Sub-Lessee to the Sub-Lessor under
            this Sub-Lease and (B) to the extent that such balance exceeds the
            aggregate of the Rentals and other payments referred to in (A)
            above, to the Sub-Lessee by way of sales agency commission.

      The Sub-Lessor irrevocably authorises and instructs the Sub-Lessee to set
      off and apply any amounts payable by the Sub-Lessee (in its capacity as
      Head-Lessor) to the Sub-Lessor (in its capacity as Lessee under the
      Head-Lease) pursuant to Clause 14.2(b) of the Head-Lease in satisfaction
      of the Sub-Lessee's right to receive the amount referred to at "thirdly"
      of Clause 12.3(a).

13    TERMINATION

13.1  TERMINATION EVENTS. The following events are Termination Events and shall
      entitle the Sub-Lessor to accelerate the Sub-Lessee's obligations under
      this Sub-Lease upon serving a notice (a "TERMINATION NOTICE") (which
      shall, in accordance with Clause 12.2(b) (Sale of the Rig), result in the
      termination of the sub-leasing), namely:

(a)   the Sub-Lessee or the Guarantor fails to pay any sum (including Rental)
      due under this Sub-Lease or any other Lease Document in full within 3
      Business Days of demand from the Sub-Lessor served on or after the due
      date or, in the case of sums payable on demand, within five (5) Business
      Days of demand;

(b)   the Sub-Lessee fails to obtain and/or maintain or procure that there are
      obtained and maintained the Required Insurances in accordance with Clause
      10 (Insurance) or if any insurer in respect of any of the Required
      Insurances cancels any of the Required Insurances or disclaims liability
      by reason, in either case, of mis-statement in any proposal for any of the
      Required Insurances or for any other failure or default on the part of any
      person (other than the Sub-Lessor);

(c)   the Sub-Lessee moving or permitting movement of the Rig outside the UKCS
      without obtaining consent in accordance with Clause 7.1 (Location and
      Movement of Rig);

(d)   the Sub-Lessee or the Guarantor shall commit or cause to be committed any
      material breach of any other term or condition of any Lease Document
      (other than those referred to in other paragraphs of this Clause 13.1) and
      the Sub-Lessee or the Guarantor as the case may be fails to remedy such
      breach within 30 days of demand so to do from the Sub-Lessor;

(e)   the Sub-Lessee ceases to be an Affiliate of the Guarantor;

(f)   any Financial Indebtedness of the Sub-Lessee or the Guarantor in an
      aggregate amount of at least twenty-five million Dollars (US$25,000,000)
      (or its equivalent in another currency) becomes or is declared due and
      payable before its stated maturity;


                                       26
<PAGE>

(g)   any representation or warranty made by the Sub-Lessee or the Guarantor in
      any Lease Document or, in each case, in any certificate, opinion or
      statement delivered or made by the Sub-Lessee or the Guarantor (or any
      officer of such person in each case) pursuant thereto proves to have been
      incorrect or inaccurate in a material respect when made or when deemed to
      be repeated on the Start Date pursuant to the terms of the relevant Lease
      Document;

(h)   any licence, authorisation, permit, consent or approval of, or
      registration with or declaration to, governmental or public bodies or
      authorities or courts required in connection with the use and operation of
      the Rig or to authorise the Sub-Lessee or the Guarantor to enter into any
      of the Lease Documents or required in connection with the validity,
      enforceability or admissibility in evidence of any of the Lease Documents
      is modified, not granted, revoked, suspended, terminated or expires or is
      not renewed or otherwise ceases to be in full force and effect in each
      case the effect of which would be to have a material adverse effect on the
      ability of the Sub-Lessee or the Guarantor to perform, or to continue to
      perform, any of their respective obligations under the Lease Documents;

(i)   the Sub-Lessee (other than as the Sub-Lessor's sales agent within the
      scope of its authority under clause 13.1(b) of the Head-Lease or in
      accordance with Clause 22.2 (Sub-Lessee)) shall sell, mortgage or execute
      a bill of sale affecting the Rig or any interest therein or any part
      thereof;

(j)   either the Sub-Lessee or the Guarantor:

      (i)   convene any meeting of creditors generally or make a deed of
            assignment or arrangement for the benefit of, or compound with, its
            creditors generally;

      (ii)  convene a meeting to consider a resolution for winding up other than
            in the course of an amalgamation or reconstruction the terms of
            which shall first have been approved in writing by the Sub-Lessor;

      (iii) have a voluntary arrangement proposed under Section 1 of the
            Insolvency Act 1986 in respect of it;

      (iv)  have a petition for winding up, dissolution or bankruptcy presented
            or any other proceeding shall be commenced and it is not dismissed
            within twenty (20) days or it shall take any step seeking the
            appointment of an administrator, trustee, receiver, administrative
            receiver, liquidator or other similar officer;

      (v)   have an encumbrancer take possession of or a receiver or an
            administrative receiver appointed over the whole or any substantial
            part of its undertaking or assets or of a substantial part of its
            assets or the Rig;

      (vi)  suffer a distress, execution, sequestration or other process being
            levied or enforced upon or sued out against the whole or any
            substantial part of the assets, rights or revenues of the Sub-Lessee
            or the Guarantor;

      (vii) admit its inability to pay its debts as they mature or be unable to
            pay its debts within the meaning of Section 123 of the Insolvency
            Act 1986;

      (viii) have any adjudication, order or, as the case may be, appointment
             made under or in relation to any of the proceedings referred to in
             Clause 13.1(j)(iv) or (vii); or


                                       27
<PAGE>

      (ix)  if an event analogous to any event referred to at sub-paragraphs (i)
            to (viii) inclusive above occurs in relation to the Sub-Lessee or
            the Guarantor under any other law applicable to the Sub-Lessee or
            the Guarantor, as the case may be;

(k)   the Guarantor denies in writing its liability under the Guarantee;

(l)   the sub-Lessee fails to comply with its obligations to issue a Voluntary
      Termination Notice in accordance with Clause 13.4(c) or Clause 13.7
      (Mandatory Prepayment).

13.2  NATURE OF TERMINATION EVENTS. The occurrence of a Termination Event,
      comprising a failure by the Sub-Lessee to comply with any of the
      provisions of a Lease Document, shall go to the root of this Sub-Lease and
      accordingly shall constitute a breach of condition which the Sub-Lessor
      may treat as a repudiation by the Sub-Lessee of this Sub-Lease. Otherwise
      a Termination Event shall constitute an agreed event giving rise to the
      Sub-Lessor's right to terminate.

13.3  CONSEQUENCES OF SERVICE OF A TERMINATION NOTICE

(a)   If by reason of the occurrence of a Termination Event the Sub-Lessor shall
      have served a Termination Notice on the Sub-Lessee, then both the
      Sub-Lessor's consent to the Sub-Lessee's possession of the Rig and the
      leasing of the Rig under this Sub-Lease shall terminate on the Leasing
      Termination Date and the provisions of Clause 12.1 shall apply.

(b)   The remedies set forth in this Clause 13.3 are not exclusive, and the
      Sub-Lessor shall be entitled to any other remedy available to the
      Sub-Lessor at law or in equity, and the Sub-Lessee shall be liable for all
      legal fees and other costs and expenses incurred by reason of the
      occurrence of any Termination Event or the exercise of the Sub-Lessor's
      remedies with respect thereto.

13.4  ILLEGALITY

(a)   If a Change of Law shall render unenforceable any of the obligations of
      any party to this Sub-Lease or any other Lease Document or makes it
      unlawful (i) for any party to any Lease Document to perform their
      respective obligations or (ii) for any such party substantially to give
      effect to their respective rights under this Sub-Lease or any other Lease
      Document entered into by it, the Sub-Lessee and the Sub-Lessor shall
      notify the other party thereof as soon as practicable after becoming aware
      thereof.

(b)   Following such notification by one party to the other, the Sub-Lessor and
      the Sub-Lessee shall discuss in good faith as to how the effects of any
      such Change of Law might be avoided so as to render the relevant
      obligations enforceable or permit the parties thereto to perform their
      obligations hereunder or thereunder or, as the case may be, to permit such
      parties substantially to give effect to their respective obligations under
      this Sub-Lease or any other Lease Document in a manner which is not
      unlawful.

(c)   If such discussions are entered into but, within thirty (30) days of
      notice being given by the affected party, or such shorter period as may be
      permitted by such law, order, regulation or official directive, or such
      change in the interpretation, administration or application thereof, the
      Sub-Lessor and the Sub-Lessee have not completed such arrangements as may
      be required to avoid the effect of any such Change of Law, then the
      Sub-Lessor shall be entitled by notice to the Sub-Lessee to require the
      Sub-Lessee to terminate the Sub-Lease Period under Clause 13.5 and the
      Sub-Lessee shall, forthwith upon receipt of such notice, issue a Voluntary
      Termination Notice having as its expiry date the date of issue of such
      Voluntary Termination Notice.

13.5  VOLUNTARY TERMINATION


                                       28
<PAGE>

(a)   The Sub-Lessee shall, subject as provided below, be entitled at any time
      to give and, in the circumstances referred to in Clause 13.4 (a), the
      Sub-Lessee shall be required to give, in each case to the Sub-Lessor an
      irrevocable written notice (the "VOLUNTARY TERMINATION NOTICE")
      terminating the leasing of the Rig under this Sub-Lease with effect from
      the Leasing Termination Date. Any voluntary Termination Notice which is
      given by the Sub-Lessee shall expire (the date of such expiry being the
      Leasing Termination Date) not less than ten (10) days after receipt of the
      same by the Sub-Lessor or, in either such case, on such earlier date as
      may be required by Clause 13.4 (c) and shall not be valid if, when issued
      by the Sub-Lessee in exercise of its entitlement so to do (rather than
      where required so to do) a Termination Event shall have occurred and be
      continuing on the date of the Voluntary Termination Notice.

(b)   If the Sub-Lessee gives a Voluntary Termination Notice, the leasing of the
      Rig shall terminate on the Leasing Termination Date and the provisions of
      Clause 12 (Return and sale of the Rig) shall apply.

(c)   No sale pursuant to the provisions of the Head-Lease following a
      termination pursuant to this Clause 13.5 shall be completed (and no
      contract for sale shall be executed) unless either the Sub-Lessor has
      received all amounts due and payable under this Sub-Lease or the
      Sub-Lessor is satisfied that, upon completion of the sale, the Sub-Lessor
      shall receive all amounts due and owing from the Sub-Lessee to the
      Sub-Lessor upon the termination of the leasing of the Rig in accordance
      with the provisons of this Sub-Lease (including the Financial Schedule).

13.6  PAYMENTS ON TERMINATION. Where the Sub-Lease Period is to terminate in
      accordance with the provisions of this Sub-Lease on the Leasing
      Termination Date by reason of the service of a Termination Notice or a
      Voluntary Termination Notice, the obligation of the Sub-Lessee to pay
      Rental under Clause 4 (Rentals) which would fall due after the Termination
      Payment Date shall cease (notwithstanding the continuation of the
      sub-leasing of the Rig until the Leasing Termination Date) and the
      Sub-Lessee shall (without prejudice to the obligations of the Sub-Lessee
      pursuant to any other provision hereof or of any other Lease Document to
      pay to the Sub-Lessor all sums which are due at the date of termination of
      the leasing of the Rig or may become due to the Sub-Lessor or be
      ascertained after such date) pay to the Sub-Lessor on the Termination
      Payment Date a sum equal to the Termination Sum together with all other
      sums then due to the Sub-Lessor hereunder PROVIDED THAT if but for the
      preceding provisions of this Clause 13.6, there would have occurred in the
      period from and including the date of service of a Termination Notice or,
      as the case may be, a Voluntary Termination Notice to and including the
      Termination Payment Date, a date which would have been a date for the
      payment of Rental under this Sub-Lease the Sub-Lessee shall on such date
      pay to the Sub-Lessor as rental (as part of the Sub-Lessor's compensation
      for early termination) an amount equal to the Rental which, but for the
      preceding provisions of this Clause 13.6, would have been payable on such
      date. Any amount so paid shall be in addition to any amounts payable by
      the Sub-Lessee to the Sub-Lessor on the Termination Payment Date pursuant
      to paragraph 2 (Termination Payment) of the Financial Schedule.

13.7  MANDATORY VOLUNTARY TERMINATION. Upon the Sub-Lessor notifying the
      Sub-Lessee in writing that:

(a)   a Total Loss has occurred in respect of the Rig;

(b)   an Environmental Claim, which is not frivolous or vexatious in the
      reasonable opinion of the Sub-Lessor, has been made in respect of the Rig
      in excess of fifty million Dollars (US$50,000,000);

(c)   an Environmental Claim, which is not frivolous or vexatious in the
      reasonable opinion of the Sub-Lessor, has been made in respect of the Rig
      against the Sub-Lessor or any other member of the Sub-Lessor's Group,


                                       29
<PAGE>

the Sub-Lessee shall, forthwith upon receipt of such notice, issue a Voluntary
Termination Notice having as its expiry date the date of issue of such Voluntary
Termination Notice.

14    GENERAL INDEMNITY

14.1  GENERAL INDEMNITY

(a)   The Sub-Lessee hereby agrees at all times to pay promptly or, as the case
      may be, indemnify and hold the Sub-Lessor and each other Indemnified
      Person harmless on a full indemnity basis from and against each and every
      Loss:

      (i)   arising directly or indirectly out of or in any way connected with
            the ownership, possession, performance, transportation, management,
            sale, import to or export from any jurisdiction, control, use or
            operation, registration, navigation, certification, classification,
            management, manning, provisioning, the provision of bunkers and
            lubricating oils, testing, design, condition, delivery to or by the
            Lessor, acceptance, leasing, sub-leasing, chartering, insurance,
            maintenance, repair, service, modification, refurbishment,
            drydocking, survey, conversion, overhaul, replacement, removal,
            repossession, return, redelivery, storage, sale, disposal the
            complete or partial removal, decommissioning, making safe,
            destruction, abandonment or loss by the Lessee or any other person
            of the Rig or caused by the Rig becoming a wreck or an obstruction
            to navigation, whether or not such Liability may be attributable to
            any defect in the Rig or to the design, construction or use thereof
            or from any maintenance, service, repair, drydocking, overhaul,
            inspection or to any other reason whatsoever (whether similar to any
            of the foregoing or not), and regardless of when the same shall
            arise (whether prior to, during or after termination of the leasing
            of the Rig under this Sub-Lease) and whether or not the Rig (or any
            part thereof) is in the possession or control of the Sub-Lessee, the
            Charterer, the Operator or any other person and whether or not the
            same is in the United Kingdom waters or abroad;

      (ii)  arising directly or indirectly out of or in any way connected with
            any Release or the threatened Release of a Hazardous Material, any
            Environmental Claim, or any breach of an Environmental Law or the
            terms and conditions of an Environmental Permit;

      (iii) as a consequence of any claim that any design, article or material
            in the Rig or any part thereof or relating thereto or the operation
            or use thereof constitutes an infringement of patent, copyright,
            design or other proprietary right;

      (iv)  in preventing or attempting to prevent the arrest, seizure, taking
            in execution, requisition, impounding, forfeiture or detention of
            the Rig or in securing or attempting to secure the release of the
            Rig in each case following the breach by the Lessee of its
            obligations under Clause 8.2 (Arrest and Detention);

      (v)   as a consequence (direct or indirect) of the breach by any person
            (other than the Sub-Lessor) of any of their respective obligations
            under any of the Lease Documents or of any of the warranties and
            representations on the part of any person (other than the
            Sub-Lessor) made in this Sub-Lease or in any of the other Lease
            Documents being untrue or inaccurate in any respect whatsoever (even
            if not a Termination Event) when made;

      (vi)  as a consequence of the occurrence of a Termination Event and/or the
            operation of Clause 13.3 (Consequence of service of a Termination
            Notice);

      (vii) any costs and expenses reasonably incurred by the Sub-Lessor or any
            other Indemnified Person or, following the occurrence of a
            Termination Event, any costs and expenses incurred by the Sub-Lessor
            or any other Indemnified Person,


                                       30
<PAGE>

            in each case in connection with the sale or Total Loss of the Rig
            (including, without limitation, broker's commissions, redelivery
            costs (if any), marketing expenses, legal costs, storage, insurance,
            registration fees and any other expenses of the Sub-Lessor or any
            other Indemnified Person incurred pending the sale or disposal of
            the Rig or otherwise in connection with the sale or disposal of the
            Rig;

      (viii) any premiums, calls, supplementary calls and contributions in
             relation to any of the Required Insurances,

      other than any amount in respect of which the Indemnified Person is
      entitled to be indemnified pursuant to Clause 16.1 (Tax Indemnity) or
      would, but for an exception contained in Clause 16.4 (Exclusions), be so
      indemnified (each of the above being referred to as a "LIABILITY").

(b)   Without prejudice to the generality of the provisions of Clause 14.1(a),
      Clause 14.1(a) shall extend to claims of persons (including Governmental
      Entities or other bodies whether corporate or otherwise) who have incurred
      expenditure in taking preventative measures against loss or damage or have
      suffered or allege that they have suffered loss, damage or injury in
      connection with anything done or omitted to be done by any person in
      relation to, in respect of, or in connection with, the Rig, including in
      connection with any Hazardous Material emanating or threatening to emanate
      from the Rig or any Environmental Claim.

(c)   The indemnities contained in Clause 14.1(a) shall extend to include:

      (i)   the Dollar cost (including fees and commissions) to the Indemnified
            Person in acquiring any currency (other than Dollars) with Dollars
            in order to satisfy or discharge in a currency other than Dollars
            any Liability;

      (ii)  all costs and interest, fees and other amounts whatsoever suffered
            or incurred by any Indemnified Person in order to fund the
            satisfaction or discharge of any Liability; and

      (iii) each Loss suffered or incurred by the Sub-Lessor in satisfying or
            discharging, or indemnifying any Indemnified Person (other than
            itself) against, any Liability, or any matter referred to in
            sub-paragraphs of clause 14.1(c)(i) or (ii) above, whether or not
            such Liability is suffered or incurred by the Sub-Lessor under any
            formal or informal arrangement, and whether or not any such formal
            or informal arrangement existed at the time the Liability was
            suffered or incurred by such Indemnified Person.

14.2  EXCLUSIONS FROM GENERAL INDEMNITY. The indemnities contained in Clause
      14.1 (General Indemnity) shall not extend to any Liability:

(a)   to the extent that such Liability is caused by any act of an Indemnified
      Person which constitutes the wilful misconduct or reckless disregard with
      knowledge of the probable consequences;

(b)   to the extent that such Liability is caused by any failure on the part of
      the Sub-Lessor to comply with any of its express and specific obligations
      under any of the Lease Documents to which the Sub-Lessor is party;

(c)   to the extent that such Liability constitutes any amounts in respect of
      Premium or Rentals payable by the Sub-Lessor under the Head-Lease;

(d)   to the extent that such Liability constitutes a cost which is expressly to
      be borne by the Sub-Lessor under any other provision of this Sub-Lease or
      the other Lease Documents and which the Sub-Lessee establishes was not
      intended to be within the scope of the


                                       31
<PAGE>

      indemnities granted in favour of the Sub-Lessor or any other Indemnified
      Person in any Lease Document;

(e)   in respect of which the Sub-Lessor is expressly and specifically
      indemnified under any other provision of this Sub-Lease.

14.3  NOTIFICATION OF INDEMNITY CLAIMS. Without prejudice to the provisions of
      this Clause 14 and without limiting in any way whatsoever, or being a
      condition precedent or subsequent to, the indemnities in favour of any
      Indemnified Person hereunder or prompt payment thereunder, the Sub-Lessor
      shall:

(a)   notify the Sub-Lessee in writing as soon as practicable after receipt by
      the Sub-Lessor of notice of a Liability (provided such notice is in
      writing). Such notification to the Sub-Lessee from the Sub-Lessor shall
      give such details as the Sub-Lessor then has and which are in all the
      circumstances reasonable having regard to the contents of the notice of a
      Liability received by the Sub-Lessor; and

(b)   subject to Clause 14.4 (Defence of Claims), notify the Sub-Lessee of the
      Sub-Lessor's intention to pay or procure the payment of any moneys in
      respect of any such Liability before any such payment is made.

14.4  DEFENCE OF CLAIMS. Without prejudice to the provisions of this Clause 14,
      the Sub-Lessee shall (subject to having first obtained the consent of the
      relevant insurers, if any, and complying in all respects with its
      obligations under this Sub-Lease and provided no Termination Event has
      occurred and is continuing) be entitled to take (at its own cost) such
      actions as the Sub-Lessee reasonably considers necessary to defend or
      avoid any liability arising in respect of a Liability including legal
      proceedings against any third party in respect of a Liability, but subject
      always to the Sub-Lessor first being indemnified to its satisfaction by
      the Sub-Lessee and/or the Guarantor against all potential losses, costs,
      damages and expenses which may be incurred or suffered by the Sub-Lessor
      in connection with any such action, provided always that the Sub-Lessee
      shall not be entitled to take any such action and shall cease taking such
      action and shall settle any Liability if the Sub-Lessor considers (in its
      reasonable opinion) that taking or continuing such action would be likely
      to (i) require the Sub-Lessor to disclose any information or documentation
      which the Sub-Lessor considers, in its reasonable opinion, to be
      confidential (ii) be harmful to the Sub-Lessor's reputation as a financial
      institution, (iii) involve it in any unlawful act or activity or any act
      or activity that is contrary to any law applicable to the Sub-Lessor or
      (iv) cause the Sub-Lessor to breach any other obligation to which it is
      subject whether under the Lease Documents or otherwise.

      Notwithstanding the foregoing provisions of this Clause 14.4, the
      Sub-Lessee shall not be entitled to take or continue any action in the
      name of the Sub-Lessor which it may otherwise be entitled to take under
      this Clause 14.4 without the prior written consent of the Sub-Lessor, such
      consent not to be unreasonably withheld or withdrawn, provided always that
      it shall be reasonable for the Sub-Lessor to withhold its consent or
      withdraw its consent once given if the Sub-Lessor determines that the use
      of its name in connection with such action would be likely to (a) be
      harmful to the Sub-Lessor Parent's reputation as a financial institution
      (such determination to be made in the Sub-Lessor's absolute discretion) or
      (b) (i) otherwise have a material adverse effect on the business of the
      Sub-Lessor or (ii) involve the Sub-Lessor in any unlawful act or activity
      or any act or activity that is contrary to any law applicable to the
      Sub-Lessor or (iii) cause the Sub-Lessor to breach any other obligation to
      which it is subject whether under the Lease Documents or otherwise (any
      such determination to be made in the reasonable opinion of the
      Sub-Lessor)).

      The Sub-Lessor and the Sub-Lessee will co-operate and consult in good
      faith in relation to the matters referred to in this Clause 14.4. In
      particular, but without limitation, the Sub-Lessee will keep the
      Sub-Lessor fully informed in respect of any proceedings which the


                                       32
<PAGE>

      Sub-Lessee is conducting in the name of the Sub-Lessor and will provide
      the Sub-Lessor with copies of any and all documentation connected with any
      such proceedings.

14.5  CURRENCY INDEMNITY

(a)   If the Sub-Lessor or any other Indemnified Person receives an amount in
      respect of the liability of the Sub-Lessee under this Sub-Lease or any
      other Lease Document or if that liability is converted into a claim,
      proof, judgment or order in a currency other than the currency (the
      "CONTRACTUAL CURRENCY") in which the amount is expressed to be payable
      under this Sub-Lease or the relevant other Lease Document:

      (i)   the Sub-Lessee shall indemnify the Sub-Lessor or the relevant
            Indemnified Person as an independent obligation against any loss or
            liability arising out of or as a result of the conversion;

      (ii)  if the amount received by the Sub-Lessor or the relevant Indemnified
            Person, when converted into the contractual currency at the
            Sub-Lessor Parent's spot rate of exchange on the relevant date, is
            less than the amount owed in the contractual currency, the
            Sub-Lessee shall forthwith on demand pay to the Sub-Lessor or the
            relevant Indemnified Person an amount in the contractual currency
            equal to the deficit; and

      (iii) the Sub-Lessee shall pay to the Sub-Lessor or the relevant
            Indemnified Person concerned on demand any exchange costs and taxes
            payable in connection with any such conversion.

(b)   The Sub-Lessee waives any right it may have in any jurisdiction to pay any
      amount under this Sub-Lease or any other Lease Document in a currency
      other than that in which it is expressed to be payable.

14.6  RECOVERIES FROM THIRD PARTIES. If any Indemnified Person shall recover
      from or be paid by, any person (other than the Sub-Lessee, the Guarantor
      or any other member of the Guarantor's Group) any amount in respect of any
      payments paid or discharged by the Sub-Lessee in accordance with this
      Clause 14, then PROVIDED THAT the Sub-Lessor has received payment of such
      amount and is satisfied, in its absolute discretion, that such amount is
      unconditionally available for retention by the Sub-Lessor, the Sub-Lessor
      shall pay to the Sub-Lessee a sum equal to the value of such recovered or
      paid amount together with any interest actually earned on such recovered
      or paid amount (less the amount of any tax payable thereon).

14.7  PASS THROUGH OF INDEMNITY BENEFITS. Where in this Clause 14 an indemnity
      is expressed to be for the benefit of any person who is not a party to
      this Sub-Lease the Sub-Lessor shall be entitled to indemnify such person
      on the same terms (and subject in particular to Clause 14.4 (Defence of
      Claims)) mutatis mutandis as the indemnities expressed to be for the
      benefit of such person in this Clause 14 and the Sub-Lessee shall
      indemnify the Sub-Lessor and hold the Sub-Lessor harmless on a full
      indemnity basis from and against each amount paid or payable by the
      Sub-Lessor to such person under any such indemnity.

14.8  PRESERVATION OF INDEMNITIES

(a)   Without prejudice to any right to damages or other claim which any party
      may, at any time, have against another under this Sub-Lease or under any
      of the Lease Documents it is hereby agreed and declared that the
      indemnities in favour of the Sub-Lessor and the other Indemnified Persons
      by the Sub-Lessee contained in this Sub-Lease or any of the Lease
      Documents shall continue in full force and effect subject to and in
      accordance with their terms notwithstanding the termination of the leasing
      of the Rig under this Sub-Lease, any sale or other disposition of the Rig,
      Total Loss or any breach of the terms hereof or thereof by the Sub-Lessee
      (including fundamental breach) or the lawful


                                       33
<PAGE>

      repudiation by the Sub-Lessor of this Sub-Lease or any of the Lease
      Documents or any other circumstances whatsoever.

(b)   If any payment received by the Sub-Lessor or an Indemnified Person in
      respect of moneys owing or due and payable by the Sub-Lessee hereunder
      shall on the subsequent liquidation or other insolvency of the Sub-Lessee
      be avoided under any laws relating to insolvency or liquidation, such
      payment shall not be considered as discharging or diminishing the
      liability of the Sub-Lessee under this Sub-Lease and the other Lease
      Documents and this Sub-Lease and the other Lease Documents shall continue
      to apply as if such payment had at all times remained owing by the
      Sub-Lessee.

15    COSTS, EXPENSES AND FEES

15.1  COSTS AND EXPENSES. The Sub-Lessee shall pay, on demand, the amount of all
      costs and expenses:

(a)   subject to the separately agreed cap, reasonably incurred by the
      Sub-Lessor in connection with the preparation, negotiation and execution
      of the Lease Documents;

(b)   reasonably incurred by the Sub-Lessor, in connection with any amendments,
      waivers or consents under or in respect of this Sub-Lease or the other
      Lease Documents instigated by the Sub-Lessee (whether or not such
      amendment, waiver or consent becomes effective) (including but not limited
      to reasonable legal fees); and

(c)   incurred by the Sub-Lessor in enforcing or defending or attempting to
      enforce or defend (or determining whether or how to enforce or defend) any
      rights under this Sub-Lease or any other Lease Document.

16    TAX INDEMNITY

16.1  INDEMNITY. Subject to Clause 16.4 (Exclusions), the Sub-Lessee shall on
      demand indemnify the Sub-Lessor and keep the Sub-Lessor fully indemnified
      against any Tax Liability imposed on or payable by the Sub-Lessor or any
      Indemnified Person which arises or becomes payable at any time in respect
      of, by reference to or arising out of:

(a)   the operation of the Rig; and

(b)   the Rig being or becoming a Fixture.

16.2  MOVEMENT OF RIG. The Sub-Lessee hereby indemnifies the Sub-Lessor and
      shall keep the Sub-Lessor fully indemnified against any Tax Liability
      imposed on or payable by the Sub-Lessor or any Indemnified Person which
      arises or becomes payable at any time in respect of, by reference to or
      arising out of:

(a)   the movement or location of the Rig;

(b)   the existence of the Rig outside the UKCS; or

(c)   the residence, domicile or activities of the Sub-Lessee or any member of
      the Guarantor's Group;

      which arise as a result of or by reference to the Sub-Lessee moving the
      Rig outside the UKCS with or (without prejudice to the provisions of
      Clause 7.1 (Location and Movement of the Rig) and the Sub-Lessor's
      remedies for any breach of that Clause) without the prior written consent
      of the Sub-Lessor.


                                       34
<PAGE>

16.3  INCREMENTAL TAX LIABILITY. Any Tax Liability referred to in clauses 16.1
      (Indemnity) and 16.2 (Movement of the Rig) shall be an "INCREMENTAL TAX
      LIABILITY" for the purposes of this Sub-Lease.

16.4  EXCLUSIONS. Subject to Clause 16.8 (Indemnity payments), the Sub-Lessee
      shall not, for the avoidance of doubt, be obliged to indemnify the
      Sub-Lessor pursuant to Clause 16.1 (Indemnity) and 16.2 (Movement of the
      Rig):

(a)   against any incremental Tax Liability in any relevant jurisdiction
      attributable to the Rentals or Termination Sum actually receivable
      hereunder or to any other amounts payable to the Sub-Lessor under the
      Lease Documents;

(b)   against any incremental Tax Liability to the extent it arises owing to the
      Sub-Lessor knowingly failing to file Tax returns or the Sub-Lessor
      knowingly failing to make a payment of Taxes which are due and payable
      assessed on the Sub-Lessor which knowing failure has not been consented to
      in writing, or requested in writing by the Sub-Lessee except where such
      knowing failure by the Sub-Lessor arises from a failure by the Sub-Lessee
      promptly to provide the Sub-Lessor with correct, suitable and adequate
      information to the extent that the Sub-Lessee is (or, but for any
      fraudulent or negligent defaults on its part, would have been) in a
      position to provide such information following receipt by the Sub-Lessee
      of a written request from the Sub-Lessor setting out full details of such
      information to enable the Sub-Lessor to file the relevant Tax return or
      pay such Taxes.

16.5  STAMP DUTIES. All stamp, documentary, registration or other like duties or
      Taxes, including any penalties, additions, fines, surcharges or interest
      relating thereto, which are imposed on or chargeable on or in connection
      with this Sub-Lease or any of the other Lease Documents shall be paid by
      the Sub-Lessee (whether or not the primary responsibility of the
      Sub-Lessee) PROVIDED THAT the Sub-Lessor shall be entitled but not obliged
      to pay any such duties or Taxes, whether or not they are its primary
      responsibility, whereupon the Sub-Lessee shall on demand indemnify the
      Sub-Lessor against those duties or Taxes. The Sub-Lessor agrees that if it
      decides to pay any such duties or Taxes, it shall give the Sub-Lessee not
      less than fifteen (15) Business Days' notice before making such payment
      (unless a Termination Event has occurred and is continuing or the
      Sub-Lessor is legally required to make payment earlier).

16.6  PAYMENTS. Any payment to be made under Clause 16.1 (Indemnity) shall be
      made:

(a)   in the case of a Tax Liability within paragraph (a) of the Tax Liability
      definition or, in the case of the set-off of a right to repayment within
      paragraph (c) of the Tax Liability definition, no later than two Business
      Days prior to the last date on which the payment of Tax can be made
      without incurring interest or penalties, and

(b)   in the case of a Tax Liability within paragraph (b) of the Tax Liability
      definition, no later than the last date on which a payment of Tax which
      would not have been due but for the loss or use of the Relief as referred
      to in that paragraph (b) can be made without incurring interest or
      penalties,

      and in any other case, or, if later, five (5) Business Days after the date
      on which notice of the incremental Tax Liability is given to the
      Sub-Lessee.

16.7  NOTICE. If the Sub-Lessor receives notice of an incremental Tax Liability
      it shall promptly give written notice to the Sub-Lessee and shall provide
      the Sub-Lessee with reasonable details of the nature and quantum of the
      incremental Tax Liability.


                                       35
<PAGE>

16.8  INDEMNITY PAYMENTS. If and to the extent that any sums payable by the
      Sub-Lessee under this Sub-Lease by way of indemnity or reimbursement prove
      to be insufficient, by reason of Taxes suffered thereon, for the
      Sub-Lessor or an Indemnified Person to discharge its relevant liability or
      to reimburse the Sub-Lessor or an Indemnified Person for the cost incurred
      by it in discharging such liability, the Sub-Lessee will on demand pay to
      the Sub-Lessor, or the Sub-Lessor for the benefit of such Indemnified
      Person, such additional sum as (after taking into account any Taxes
      suffered by the Sub-Lessor and/or the Indemnified Person thereon) is
      required to indemnify on an after-Tax basis the Sub-Lessor or, as the case
      may be, the Indemnified Person in respect of such insufficiency.

16.9  MITIGATION. In the event of a Change of Law or in the event of any Tax
      Liability arising which was not contemplated by the parties on entry into
      this Agreement, any of the other Lease Documents or any transaction or
      document contemplated herein or therein, the Sub-Lessor and the Sub-Lessee
      hereby agree to co-operate in good faith to seek to mitigate or eliminate
      any adverse consequences of such Change of Law or such Tax Liability,
      including without limitation by way of amendment or revision to this
      Sub-Lease, any of the other Lease Documents or any transaction or document
      contemplated herein or therein or otherwise restructuring the transaction
      contemplated by the Lease Documents.

17    INCREASED COSTS

17.1  INCREASED COSTS. This Clause 17 applies if at any time the Sub-Lessor
      notifies the Sub-Lessee that it considers that as a result of:

(a)   any Change of Law; or

(b)   the effect of complying with any regulation (including any which relates
      to capital adequacy or liquidity controls or which affects the manner in
      which the Sub-Lessor is obliged to allocate capital resources) which is
      introduced, or altered, or the interpretation or application of which is
      altered, after the date of this Sub-Lease,

      the Sub-Lessor or any member of the Sub-lessor's Group has incurred or
      will incur an "INCREASED COST".

17.2  MEANING OF "INCREASED COST". In this Clause 17, "INCREASED COST" means, in
      relation to the Sub-Lessor or any member of the Sub-lessor's Group:

(a)   an additional or increased cost incurred directly as a result of, or in
      connection with, the Sub-Lessor having entered into, or being a party to,
      the Lease Documents or funding, maintaining or performing its obligations
      under the Lease Documents; or a reduction in the amount of any payment to
      the Sub-Lessor under any of the Lease Documents or in the effective return
      which such a payment represents to the Sub-Lessor or on its capital; or

(b)   an additional or increased cost of funding all or maintaining all or any
      of the Sub-Lessor's liabilities under the Head-Lease; or

(c)   a liability to make a payment, or a return foregone, which is calculated
      by reference to any amounts received or receivable by the Sub-Lessor under
      this Sub-Lease or any of the other Lease Documents;

      but not an item directly covered by the current capital adequacy
      regulations in force on the date of this Sub-Lease which include (but are
      not limited to) the matters set out in the initial statement of the Basle
      Committee on Banking Regulations and Supervisory


                                       36
<PAGE>

      Practices dated July 1988 and entitled "International Convergence of
      Capital Measurement and Capital Standards" (the "BASLE ACCORD").

      For the avoidance of doubt, any item arising from matters set out in the
      new Basle Accord (expected in 2007) in the form finally implemented by the
      applicable authorities ("BASLE II") shall count as increased costs for the
      purpose of this Clause to the extent and according to the timetable
      provided for. Without prejudice to the Sub-Lessor's right to use this
      Clause to claim an increased cost the Sub-Lessor will consult with the
      Sub-Lessee in good faith and in a timely manner in relation to the
      implementation and effect of Basle II insofar as the same relates to
      Increased Costs within this Clause 17.

17.3  PAYMENT OF INCREASED COSTS. The Sub-Lessee shall pay to the Sub-Lessor the
      amounts which the Sub-Lessor from time to time notifies the Sub-Lessee
      that it has determined is necessary to compensate it for the increased
      cost. The Sub-Lessor shall provide the Sub-Lessee with reasonable detail
      of the basis on which it seeks to recover any amount in respect of an
      increased cost.

17.4  MITIGATION. If circumstances arise which would result in notification
      under Clause 17.1(Increased Costs) then, without limiting the rights of
      the Sub-Lessor under Clause 17.3 (Payment of Increased Costs), the
      Sub-Lessor shall use its reasonable endeavours to take such reasonable
      steps as may be open to it to mitigate or remove those circumstances
      PROVIDED THAT the Sub-Lessor shall be under no obligation to take any such
      steps which shall or might be considered likely in the Sub-Lessor's
      opinion to:

(a)   have an adverse effect in the Sub-Lessor's business operations, financial
      condition or reputation;

(b)   involve the Sub-Lessor in any activity which is unlawful or prohibited or
      any activity which is contrary to, or inconsistent with, any regulation;
      or

(c)   involve it in any expense (unless indemnified to its satisfaction) or Tax
      disadvantage.

18    RELEASE FROM ARREST

18.1  RELEASE FROM ARREST: SUB-LESSOR'S VESSELS. If any vessel which is for the
      time being owned (in whole or in part) by or leased to the Sub-Lessor
      shall at any time have a writ or libel filed against it or be arrested,
      attached or levied upon pursuant to any legal process or purported legal
      process or is detained in exercise or purported exercise of any
      Encumbrance or claim of whatsoever nature, arising out of the use or
      operation of the Rig or out of the use or operation of any other rig
      vessel owned by or leased or chartered to the Sub-Lessee or any other
      member of the Guarantor's Group, except where that Encumbrance or claim
      arises as a result of any act or omission of the Sub-Lessor (but excluding
      for this purpose any act or omission relating to the operation of the Rig
      for which the Sub-Lessee is responsible pursuant to this Sub-Lease or any
      act or omission consequent upon an act or omission of the Sub-Lessee or
      any other member of the Guarantor's Group):

(a)   the Sub-Lessee forthwith upon receiving notice thereof at its expense
      shall procure the release of such vessel from such arrest, detention,
      attachment or levy or, as the case may be, the discharge of the writ or
      libel by providing bail or procuring the provision of security or
      otherwise as the circumstances may require; and


                                       37
<PAGE>

(b)   the Sub-Lessee shall be responsible for discharging each and every
      liability in connection with any such process, claim, Encumbrance or other
      action.

      Without prejudice to the generality of the other indemnities contained in
      this Sub-Lease, should any such other vessel owned by or leased to the
      Sub-Lessor be arrested, detained, attached or levied upon or be the
      subject of a writ or libel in such circumstances, the Sub-Lessee shall
      indemnify the Sub-Lessor against all claims made on the Sub-Lessor by the
      charterers of such other vessel or any other party in connection with such
      arrest, detention, attachment, levy, writ or libel.

18.2  RELEASE FROM ARREST: SUB-LESSEE'S VESSELS. If:

(a)   the Rig or any other rig or vessel owned or operated by any member of the
      Guarantor's Group, at any time has a writ or libel filed against it or is
      arrested, attached or levied upon pursuant to any legal process or
      purported legal process or is detained in exercise or purported exercise
      of any Encumbrance or claim of whatsoever nature arising out of the use or
      operation of any other rig or vessel for the time being owned by or leased
      to the Sub-Lessor or any other member of the Sub-Lessor Group and leased
      or chartered by it otherwise than to the Sub-Lessee or to any member of
      the Guarantor's Group; and

(b)   the charterers of such other vessel (being in that situation under
      obligations to the Sub-Lessor equivalent to those assumed by the
      Sub-Lessee under Clause 8.3 (Arrest and Detention)) fail to fulfil those
      obligations,

      PROVIDED THAT the Sub-Lessee shall first have given prior notice thereof
      to the Sub-Lessor and, to the extent practicable, consulted with the
      Sub-Lessor as far in advance as is reasonable in all the circumstances,
      the Sub-Lessee shall:

      (i)   be entitled to act as agent for the Sub-Lessor or the relevant
            member of the Sub-Lessor Group (as the case may be) to procure
            release of the Rig or such other rig or vessel (as the case may
            require) from such arrest, detention, attachment or levy or, as the
            case may be, the discharge of the writ or libel and the discharge of
            all liabilities in connection with such process, claim, lien or
            other action subject to and in accordance with Clause 14.4 (Defence
            of claims), mutatis mutandis; and

      (ii)  be entitled to be indemnified by the Sub-Lessor against claims made
            on the Sub-Lessee by the charterers of such other vessel in
            connection with such arrest, detention, attachment, levy, writ or
            libel and all losses and expenses reasonably and properly incurred
            in connection therewith.

19    RIGHTS AND WAIVERS

19.1  RIGHTS CUMULATIVE. No right or remedy conferred upon the Sub-Lessor or the
      Sub-Lessee by this Sub-Lease shall be exclusive of any right or remedy
      provided by law, and all rights and remedies conferred upon the Sub-Lessor
      or the Sub-Lessee by this Sub-Lease shall be cumulative with, and in
      addition to, its rights under general law and, in particular, shall be
      without prejudice to the Sub-Lessor's or the Sub-Lessee's rights to claim
      damages.

19.2  NO WAIVER. The exercise of any power or remedy or the enforcement of any
      right by the Sub-Lessor or Sub-Lessee shall not be construed as a waiver
      of the right to exercise any other power or remedy or to enforce any other
      right. Any forbearance or indulgence granted by the Sub-Lessor or
      Sub-Lessee shall not constitute a waiver of the right or remedy of the
      Sub-Lessor or Sub-Lessee respectively in respect of which such


                                       38
<PAGE>

      forbearance or indulgence is granted and the Sub-Lessor or Sub-Lessee
      respectively shall be entitled to exercise such right or remedy at any
      time thereafter.

20    NOTICES

20.1  METHOD. Any demand, notice or other communication to be given under or in
      connection with this Sub-Lease shall be given in writing in English and,
      unless otherwise provided, shall be made by fax or letter in writing and
      sent by first class prepaid letter post, by fax or delivered by hand to
      the addressee at its address set out below.

20.2  REQUIRED ADDRESS. Any notice or other communication to be given by one
      party to another under this Lease shall (unless one party has by fifteen
      (15) days' notice to the other party specified another address) be given
      to that other party at the respective addresses given below.

20.3  DETAILS. The addresses and fax numbers of the Sub-Lessor and the
      Sub-Lessee are:

      Sub-Lessor:

      Sogelease B.V.
      Rembrant Tower
      Amstelplein 1
      1096 HA
      Amsterdam
      The Netherlands

      Fax:  + 31 20 463 5358

      Attention:  Head of Lease Administration

      Sub-Lessee:

      GlobalSantaFe Drilling Company (North Sea) Limited
      Langlands House
      Huntly Street
      Aberdeen   AB10 1SH
      Scotland

      Fax:        + 44 1224 654680

      Attention:  Legal Department

      with a copy to:

      GlobalSantaFe Corporation
      15375 Memorial Drive
      Houston
      Texas  77079
      USA

      Fax:        + 281 925 6675

      Attention:  Legal Department

20.4  DEEMED RECEIPT. Any notice or other communication given by one party to
      the other shall be deemed to have been received:


                                       39
<PAGE>

(a)   if sent by fax, with a confirmed receipt of transmission from the
      receiving machine, on the day on which transmitted;

(b)   in the case of a written notice given by hand, on the day of actual
      delivery to the addressee; and

(c)   if posted, on the second Business Day following the day on which it was
      despatched by first class mail postage prepaid or,

      PROVIDED THAT a notice given in accordance with the above but received on
      a day which is not a Business Day or after normal business hours in the
      place of receipt shall only be deemed to have been received on the next
      Business Day.

21    LAW AND JURISDICTION

21.1  ENGLISH LAW. This Sub-Lease is governed by and shall be construed in
      accordance with English law.

      The parties agree that the courts of England shall have exclusive
      jurisdiction to settle any disputes which may arise in connection with
      this Sub-Lease. By its execution and delivery of this Sub-Lease, the
      Sub-Lessor:

(a)   hereby accepts for itself and in respect of its property, generally and
      unconditionally, the jurisdiction of the aforesaid courts;

(b)   waives any objections on the grounds of venue or forum non conveniens or
      any similar grounds and agrees that legal proceedings in any one or more
      jurisdictions shall not preclude legal proceedings in any other
      jurisdiction; and

(c)   agrees that final judgment against it in any action or proceedings shall
      be conclusive and may be enforced in any other jurisdiction within or
      outside England by suit on the judgment, a certified copy of which shall
      be conclusive evidence of the fact and of the amount of its indebtedness.

21.2  APPOINTMENT OF PROCESS AGENT. The Sub-Lessor hereby appoints the London
      office for the time being of Societe Generale to receive, for and on
      behalf of itself, service of process in England in any legal proceedings
      with respect to this Sub-Lease. Should Societe Generale cease to have an
      office in London during the period of this Sub-Lease, the Sub-Lessor
      shall, in a timely manner, appoint another agent for service of process
      for England and confirm the same to the Sub-Lessor.

22    ASSIGNMENT

22.1  SUB-LESSOR. The Sub-Lessor may, at its own expense, assign or otherwise
      transfer by way of sale its rights to Rentals, Termination Sums and other
      amounts payable under this Sub-Lease to any party without the prior
      written consent of the Sub-Lessee. The liabilities of the Sub-Lessee shall
      not be increased, following any such assignment or transfer from what they
      would otherwise have been but for such assignment or transfer. In the
      event that the Sub-Lessee suffers any increased cost as a result of such
      assignment or transfer, the Sub-Lessor shall indemnify the Sub-Lessee
      against any such increased cost. Any other assignment or transfer of the
      rights or obligations of the Sub-Lessor under this Sub-Lease shall require
      the prior written consent of the Sub-Lessee.

22.2  SUB-LESSEE. The Sub-Lessee may assign or otherwise transfer all (but not
      part only) of its rights and obligations under this Sub-Lease to another
      Affiliate of the Guarantor which


                                       40
<PAGE>

      is incorporated in either England and Wales or Scotland (the "TRANSFEREE")
      PROVIDED THAT in connection with and as a condition to such transfer:

      (i)   the Transferee also acquires ownership of the Rig and (by novation
            or otherwise documented to the satisfaction of the Sub-Lessor,
            acting reasonably) all the rights and obligations of the Head-Lessor
            under the Head-Lease;

      (ii)  the obligations of the Transferee are guaranteed by the Guarantor on
            the terms by the Guarantee, mutatis mutandis;

      (iii) the Sub-Lessor receives such evidence of due corporate authorisation
            by the Sub-Lessee, the Transferee and the Guarantor in relation to
            the matters outlined above and such favourable legal opinions as it
            shall require, in each case acting reasonably.

      Any assignment or transfers of all or any part of the Sub-Lessee's rights
      or obligations under this Sub-Lease, otherwise than in accordance with the
      foregoing provisions of this Clause 22.2, shall require the prior written
      consent of the Sub-Lessor.

23    GENERAL

23.1  CERTIFICATE. A certificate by a duly authorised officer of the Sub-Lessor
      as to any amount owing under this Sub-Lease shall be prime facia evidence
      of the amount owing.

23.2  ILLEGALITY. If any provision of this Sub-Lease is or becomes illegal,
      invalid or unenforceable in any respect in any jurisdiction, neither the
      legality, validity or enforceability of:

(a)   such provision in any other jurisdiction; or

(b)   any other provision hereof in such or any other jurisdiction,

      shall in any way be affected or impaired.

23.3  SET-OFF. Notwithstanding any other provisions hereof, the Sub-Lessor shall
      be entitled to set-off or withhold from any amounts expressed in this
      Sub-Lease and in the Head-Lease to be payable to the Sub-Lessee (whether
      as lessee under this Sub-Lease or as lessor under the Head-Lease) by the
      Sub-Lessor (whether as lessor under this Sub-Lease or as lessee under the
      Head-Lease) any amounts due and payable from the Sub-Lessee (whether as
      lessee under this Sub-Lease or as lessor under the Head-Lease) to the
      Sub-Lessor (whether as lessor under this Sub-Lease or as lessee under the
      Head-Lease) under the Sub-Lease or any of the other Lease Documents.

23.4  CONFIDENTIALITY. Each of the parties hereto undertakes to the other party
      not to disclose (without the other party's prior written consent) to any
      third party any information relating to the transactions effected by the
      Lease Documents, PROVIDED THAT the restrictions contained in this Clause
      23.4 shall not apply to:

(a)   any information which has become part of public knowledge or literature
      (except through a breach of this Clause 23.4);

(b)   any disclosure to any of its Affiliates or to any of its or its
      Affiliates' agents or advisers; or


                                       41
<PAGE>

(c)   any disclosure to any actual or potential or assignee, PROVIDED THAT no
      such disclosure may be made without the disclosing party first obtaining
      from the other party concerned suitable undertakings as to
      confidentiality; or

(d)   to the extent required by law or applicable regulation (including
      regulations of the US Securities Exchange Commission) or in connection
      with any proceedings for enforcement of rights or benefits, or protection
      of rights or benefits, under any Lease Document, or required by any
      governmental, regulatory or taxing authority.

23.5  NO THIRD PARTY RIGHTS. No term of this Sub-Lease is enforceable under the
      Contracts (Rights of Third Parties) Act 1999 by a person who is not a
      party to this Sub-Lease.

23.6  COUNTERPARTS. The Sub-Lease may be executed in any number of counterparts
      and this will have the same effect as if the signatures on the
      counterparts were on a single copy of this Sub-Lease.

AS WITNESS the hands of duly authorised representatives of the parties hereto
the day and year first above written.


                                       42
<PAGE>

                                   SCHEDULE 1

                                     THE RIG

<TABLE>
<S>                                         <C>
              Type:                         Jack-Up Drilling Unit

              Overall Dimensions:           224 by 200 by 25 feet

              Legs (4):                     324 ft. long triangular

              Design:                       Breit Engineering

              Year of Build:                1968

              Class:                        ABS
</TABLE>


                                       43
<PAGE>

                                   SCHEDULE 2

                            CERTIFICATE OF ACCEPTANCE

Certificate of Acceptance dated [-] January 2003 pursuant to a Sub-Lease
Agreement dated [-] January 2003 (the "SUB-LEASE") between (1) Sogelease BV as
Sub-Lessor and (2) GlobalSantaFe Driling Company (North Sea) Limited as
Sub-Lessee.

Terms used in this Certificate of Acceptance shall have the meaning given to
such terms in the Sub-Lease in accordance with the terms thereof.

The Sub-Lessor and the Sub-Lessee hereby confirm that the Rig has been delivered
by the Sub-Lessor to the Sub-Lessee and accepted by the Sub-Lessee from the
Sub-Lessor under the Sub-Lease subject to the provisions of Clause 2.1 (Quiet
Enjoyment) of the Sub-Lease.

This Certificate of Acceptance is a Lease Document.

SIGNED
by
for and on behalf of
SOGELEASE B.V.

SIGNED
by
for and on behalf of
GLOBALSANTAFE DRILLING COMPANY (NORTH SEA) LIMITED


                                       44
<PAGE>

                                   SCHEDULE 3

                               FINANCIAL SCHEDULE

1     RENTALS

(a)   During the Sub-Lease Period Rentals shall be payable in advance on each
      Rental Payment Date. The amount of Rental payable on each such Rental
      Payment Date shall be US$8,000,000 (excluding VAT and except the Start
      Date) plus or minus any Additional Rental.

(b)   The "ACTUAL BALANCE" on any date is as follows:

      (i)   if the previous Adjustment Date was a Rental Payment Date, the sum
            of (x) the Notional Balance at the previous Adjustment Date and (y)
            interest at the Actual Rate for the number of days since the
            previous Adjustment Date applied to the Notional Balance; or

      (ii)  if the previous Adjustment Date was not a Rental Payment Date, the
            sum of (x) the Actual Balance on the previous Adjustment Date and
            (y) interest at the Actual Rate for the number of days since the
            previous Adjustment Date applied to such Actual Balance.

      Such calculations to be made on the basis of a year of three hundred and
      sixty (360) days.

<TABLE>
<CAPTION>
                   ADJUSTMENT DATES                 NOTIONAL BALANCE
<S>                                                 <C>
                   Start Date                        $30,478,500.00
                   06/05/2003                        $30,478,500.00
                   04/08/2003                        $30,478,500.00
                   03/11/2003                        $30,478,500.00
                   03/02/2004                        $23,080,375.78
                   04/05/2004                        $23,080,375.78
                   03/08/2004                        $23,080,375.78
                   03/11/2004                        $23,080,375.78
                   03/02/2005                        $15,537,414.68
                   03/05/2005                        $15,537,414.68
                   03/08/2005                        $15,537,414.68
                   03/11/2005                        $15,537,414.68
                   03/02/2006                        $7,844,240.50
                   03/05/2006                        $7,844,240.50
                   03/08/2006                        $7,844,240.50
                   03/11/2006                        $7,844,240.50
                   05/02/2007                           $(0.00)
                   03/05/2007                           $(0.00)
</TABLE>


                                       45
<PAGE>

<TABLE>
<S>                                                     <C>
                   03/08/2007                           $(0.00)
                   05/11/2007                           $(0.00)
</TABLE>

2     TERMINATION PAYMENT

(a)   The Termination Sum shall be payable on the Termination Payment Date or,
      as the case may be, the Total Loss Payment Date and shall be calculated by
      reference to such date and shall be the aggregate of the Actual Balance on
      that date and Broken Funding Costs and any other amounts then payable to
      the Sub-Lessor under the Sub-Lease and other Lease Documents.

(b)   Payments pursuant to this paragraph 2 shall bear interest from the
      Termination Payment Date or, as the case may be, the Total Loss Payment
      Date to the date of actual payment in accordance with Clause 5.2.

(c)   The Sub-Lessee undertakes and agrees to indemnify the Sub-Lessor on demand
      against any cost or detriment (including, without limitation, any damages,
      penalties or premiums incurred by the Sub-Lessor) as reasonably determined
      by the Sub-Lessor and certified to the Sub-Lessee by the Sub-Lessor,
      arising to the Sub-Lessor as a result of the Sub-Lessor repaying prior to
      its specified maturity any funding assumed to be obtained by the
      Sub-Lessor in respect of the Sub-Lessor's obligations in consequence of
      any termination of the Sub-Lease Period ("BROKEN FUNDING Costs"). If in
      consequence of such a repayment having been unconditionally received in
      full a benefit (as reasonably determined by the Sub-Lessor and certified
      to the Sub-Lessee by the Sub-Lessor) accrues to the Sub-Lessor in
      connection with any early repayment of such funding ("BROKEN FUNDING
      BENEFITS"), the Sub-Lessor undertakes to pay the Sub-Lessee promptly an
      amount equal to such benefit. If the Sub-Lessor is unable to repay such
      funding actually entered into by the Sub-Lessor, it shall notify the
      Sub-Lessee of the Sub-Lessor's best estimate in good faith (but which in
      the absence of manifest error shall be final and binding upon the
      Sub-Lessee).

      For the purpose of this paragraph 2(c) it shall be assumed that the
      Sub-Lessor has obtained funding under which interest is paid in advance on
      each Rental Payment Date and is calculated at LIBOR prevailing at the
      commencement of each Rental Period and which does not impose any penalty
      or additional cost other than by reference to the interest differential
      applying in respect of the balance of the current Rental Period in which
      prepayment occurs.

3.    DEFINITIONS

      "ACTUAL RATE" means the aggregate of LIBOR and 0.625 per cent.;

      "ADDITIONAL RENTAL" means the Actual Balance less the Notional Balance
      less the Rental due on that date on each Rental Payment Date;

      "ADJUSTMENT DATE" means each of the dates specified as such in paragraph 1
      (b) above.

      "ADJUSTMENT PERIOD" means each successive quarterly period ending on an
      Adjustment Date, the first commencing on the Start Date and the last
      ending on the last day of the Sub-Lease Period;

      "BANK" means Societe Generale, London Branch;

      "LIBOR" means in relation to any Adjustment Period, or other relevant
      period for which LIBOR is to be determined, as appropriate:


                                       46
<PAGE>

(a)   the rate for Dollar deposits for the number of months (rounded to the
      nearest whole number) comprised in the relevant Adjustment Period or other
      relevant period designated as the British Bankers Association's Interest
      Settlement Rate as quoted on the Dow Jones/Telerate Monitor as Telerate
      Page No. 3750 as at or about 11.00 a.m. (London time) two (2) London
      Business Days before the date on which the relevant Adjustment Period or
      other relevant period commences;

(b)   if such rate is not determinable, the arithmetic mean rounded up to five
      decimal places of the equivalent rates quoted to the Bank by each of the
      Reference Banks as their offered rate for such deposits for such periods;

(c)   if neither (a) or (b) above is determinable, then the equivalent rate
      determined by the Bank to the rate of interest offered to it by prime
      banks in the London Interbank Market for such deposits for such periods;

"NOTIONAL BALANCE" means those amounts specified as such in paragraph 1 (b); and

"REFERENCE BANKS" means Lloyds TSB plc, Barclays Bank plc and The Royal Bank of
Scotland plc.


                                       47
<PAGE>

                                 EXECUTION PAGE

SIGNED for and on behalf of   )
SOGELEASE B.V.                )   /s/ Niek Volkers
by Niek Volkers              )

Witness to the above signature:

Neill Proudfoot
...............................

SIGNED for and on behalf of   )
GLOBALSANTAFE DRILLING        )
COMPANY (NORTH SEA)           )   /s/ Walter Andrew Baker
LIMITED                       )
by Walter Andrew Baker        )

Witness to the above signature:

A. Drage
...............................


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