SECOND AMENDMENT TO CREDIT AGREEMENT

Exhibit 10.1

[Execution Version]

SECOND AMENDMENT TO CREDIT AGREEMENT

This SECOND AMENDMENT TO CREDIT AGREEMENT (this “ Amendment ”) is entered into as of July 31, 2009 by and among the parties hereto for the purpose of amending that certain Credit Agreement dated as of June 12, 2008 (as amended, supplemented, or otherwise modified from time to time, the “ Credit Agreement ”), by and among Emerald Driller Company (“ Borrower 1 ”), Sapphire Driller Company (“ Borrower 2 ”), Aquamarine Driller Company (“ Borrower 3 ”), Topaz Driller Company (“ Borrower 4 ”), Vantage Drilling Company and certain subsidiaries of Vantage Drilling Company party thereto (the “ Guarantors ”), the lenders from time to time party thereto (the “ Lenders ”) referred to therein, Natixis as Facility Agent and Collateral Agent, and Natixis, BTMU Capital Corporation, and Fortis Bank S.A./N.V., New York Branch, as Mandated Lead Arrangers and Joint Bookrunners (as defined in the Credit Agreement).

WHEREAS, pursuant to the Consent and First Amendment to the Credit Agreement dated as of December 22, 2008, availability of the Term Tranche 3 Commitments, Term Tranche 4 Commitments, Top-Up Tranche 1 Commitments in excess of $10,800,000, Top-Up Tranche 2 Commitments, Top-Up Tranche 3 Commitments, Top-Up Tranche 4 Commitments, and Revolving Commitments in excess of $10,000,000 were conditioned on receipt of commitments therefor from lenders acceptable to the Joint Bookrunners, and the Parent and Borrower 3 and/or Borrower 4, as applicable, were authorized to seek alternative financing for Rig 3 and Rig 4;

WHEREAS, the Parent has arranged for alternative financing for Rig 3 and Rig 4 from third party lenders, and in connection therewith has requested that the liens with respect to Rig 3 and Rig 4 be released;

WHEREAS, the Mandated Lead Arrangers and the Lenders have agreed to release such liens, and the Mandated Lead Arrangers, the Lenders, and Borrower 1, Borrower 2, Borrower 3, and Borrower 4 have agreed to amend the Credit Agreement in connection therewith, all as described below.

NOW, THEREFORE, in consideration of the premises and the mutual agreements, representations and warranties set forth herein, and for other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereto hereby agree as follows:

Section 1. Defined Terms . Unless otherwise defined in this Amendment, each capitalized term used in this Amendment has the meaning given such term in the Credit Agreement.

Section 2. Amendment of Credit Agreement .

(a) The first paragraph of the preamble of the Credit Agreement is hereby amended by replacing it in its entirety with the following:

This Credit Agreement dated as of June 12, 2008 is among Emerald Driller Company, a Cayman Islands exempted company (“ Borrower 1 ”), Sapphire

Driller Company, a Cayman Islands exempted company (“ Borrower 2 ; together with Borrower 1, the “ Borrowers ”), the Guarantors (as defined below), the Lenders, and Natixis, as Facility Agent and Collateral Agent for the Lenders.

(b) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Aggregate Commitment ” in its entirety with the following:

“ Aggregate Commitment ” means, for any Lender, the sum of such Lender’s Term Tranche 1 Commitment, Term Tranche 2 Commitment, Top-Up Tranche 1 Commitment, and Revolving Commitment.

(c) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Aggregate Revolving Commitments ” in its entirety with the following:

“ Aggregate Revolving Commitments ” means the sum of the aggregate Revolving Commitments of the Lenders. The Aggregate Revolving Commitments of the Lenders as of the effective date of the Second Amendment are $10,000,000.

(d) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Aggregate Term Commitments ” in its entirety with the following:

“ Aggregate Term Commitments ” means the sum of the aggregate Term Tranche 1 Commitments and Term Tranche 2 Commitments of the Lenders.

(e) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Aggregate Top-Up Commitments ” in its entirety with the following:

“ Aggregate Top-Up Commitments ” means the sum of the aggregate Top-Up Tranche 1 Commitments of the Lenders.

(f) Section 1.01 of the Credit Agreement is hereby amended by replacing the pricing grid within the definition of “ Applicable Margin ” in its entirety with the following:

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(g) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Applicable Maturity Date ” in its entirety with the following:

“ Applicable Maturity Date ” means, with respect to any Tranche, the Rig 1 Maturity Date or the Rig 2 Maturity Date.

(h) Section 1.01 of the Credit Agreement is hereby amended by deleting “Rig 3” and “Rig 4” from the parenthetical of the definition of “ Bidding Entity ”.

(i) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Delivery Date ” in its entirety with the following:

“ Delivery Date ” means either the Rig 1 Delivery Date or the Rig 2 Delivery Date, as the context may require.

(j) Section 1.01 of the Credit Agreement is hereby amended by adding the following Subsidiaries to the definition of “ Excluded Entity ”: P2020 Rig Co and its Subsidiaries, P2021 Rig Co and its Subsidiaries, Vantage Int’l Management (Caymans), any Charter Entity, and any future Subsidiary of the Parent (other than a Subsidiary of any other Loan Party) that does not own, charter, manage, bid for, administer, provide services to or receive services from, or otherwise enter into transactions with any Loan Party or any assets of any Loan Party.

(k) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Final Maturity Date ” in its entirety with the following:

“ Final Maturity Date ” means the earlier of (a) September 10, 2016 and (b) the earlier acceleration of all Obligations pursuant to Article VII .

(l) Section 1.01 of the Credit Agreement is hereby amended by removing “Vantage Int’l Management (Caymans)” from the definition of “ Guarantor ”.

(m) Section 1.01 of the Credit Agreement is hereby amended by deleting clause (f) of the definition of “ Interest Period ” in its entirety.

(n) Section 1.01 of the Credit Agreement is hereby amended by inserting the following sentence at the end of the definition of “ Permitted Operating Expenses ”:

For the avoidance of doubt, Permitted Operating Expenses shall not include any amounts that would be reported as “General and Administrative” on the Parent’s consolidated income statement in accordance with GAAP.

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(o) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Rig ” in its entirety with the following:

“ Rig ” means either Rig 1 or Rig 2, and “ Rigs ” means both Rigs collectively.

(p) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Rig Construction Contracts ” in its entirety with the following:

“ Rig Construction Contracts ” means the Rig 1 Construction Contract and the Rig 2 Construction Contract.

(q) Section 1.01 of the Credit Agreement is hereby amended by deleting the following definitions in their entirety: “ Revolving Tranche 3 Advance ”, “ Revolving Tranche 4 Advance ”, “ Rig 3 Delivery Date ”, “ Rig 3 Maturity Date ”, “ Rig 4 Delivery Date ”, “ Rig 4 Maturity Date ”, “ Term Tranche 3 Advance ”, “ Term Tranche 3 Borrowing ”, “ Term Tranche 3 Commitment ”, “ Term Tranche 4 Advance ”, “ Term Tranche 4 Borrowing ”, “ Term Tranche 4 Commitment ”, “ Top-Up Tranche 2 Advance ”, “ Top-Up Tranche 2 Borrowing ”, “ Top-Up Tranche 2 Commitment ”, “ Top-Up Tranche 3 Advance ”, “ Top-Up Tranche 3 Borrowing ”, “ Top-Up Tranche 3 Commitment ”, “ Top-Up Tranche 4 Advance ”, “ Top-Up Tranche 4 Borrowing ”, “ Top-Up Tranche 4 Commitment ”, “ Tranche 3 Advances ”, “ Tranche 4 Advances ”, “ Tranche 3 Commitment ”, and “ Tranche 4 Commitment ”.

(r) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Term Advance ” in its entirety with the following:

“ Term Advance ” means any Term Tranche 1 Advance or Term Tranche 2 Advance.

(s) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Term Borrowing ” in its entirety with the following:

“ Term Borrowing ” means any Term Tranche 1 Borrowing or Term Tranche 2 Borrowing.

(t) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Term Commitment ” in its entirety with the following:

“ Term Commitment ” means, for each Lender, such Lender’s Term Tranche 1 Commitment and Term Tranche 2 Commitment.

(u) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Top-Up Advance ” in its entirety with the following:

“ Top-Up Advance ” means any Top-Up Tranche 1 Advance.

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(v) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Top-Up Borrowing ” in its entirety with the following:

“ Top-Up Borrowing ” means any Top-Up Tranche 1 Borrowing.

(w) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Top-Up Commitment ” in its entirety with the following:

“ Top-Up Commitment ” means, for each Lender, such Lender’s Top-Up Tranche 1 Commitment.

(x) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Top-Up Tranche 1 Commitment ” in its entirety with the following:

“ Top-Up Tranche 1 Commitment ” means, for each Lender, the commitment of such Lender to make Top-Up Tranche 1 Advances to Borrower 1 in the maximum aggregate amount set forth on Annex I opposite such Lender’s name as its Top-Up Tranche 1 Commitment.

(y) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Tranche ” in its entirety with the following:

“ Tranche ” means any Class of Commitments or Advances, whether such Advances or Commitments are Tranche 1 Advances, Tranche 2 Advances, Tranche 1 Commitments or Tranche 2 Commitments, as the case may be.

(z) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Tranche 2 Advances ” in its entirety with the following:

“ Tranche 2 Advances ” means any Revolving Tranche 2 Advance or Term Tranche 2 Advance.

(aa) Section 1.01 of the Credit Agreement is hereby amended by replacing the definition of “ Tranche 2 Commitments ” in its entirety with the following:

“ Tranche 2 Commitment ” means any Term Tranche 2 Commitment.

(bb) Section 1.01 of the Credit Agreement is hereby amended by inserting the following definitions of “ Charter Entity ”, “ P2020 Rig Co ”, “ P2021 Rig Co ”, “ Permitted Overhead Expenses ”, and “ Second Amendment ” in appropriate alphabetical order:

“ Charter Entity ” means any Subsidiary of the Parent formed for the purpose of serving as a charter party for Rig 3 or Rig 4, so long as such Subsidiary is not a charterer or charteree of Rig 1 or Rig 2.

“ P2020 Rig Co ” means P2020 Rig Co, a Cayman Islands exempted company.

“ P2021 Rig Co ” means P2021 Rig Co, a Cayman Islands exempted company.

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“ Permitted Overhead Expenses ” means, for the Parent, that portion of amounts reported as “General and Administrative” on the Parent’s consolidated income statement in accordance with GAAP which are related to Rig 1 or Rig 2 or for non-Rig specific purposes, but not to exceed an amount equal to (a) through and including December 31, 2009, $6,500 per Rig per day, and (b) thereafter, $5,000 per Rig per day. For the avoidance of doubt, amounts included in the Parent’s consolidated account of General and Administrative expenses which pertain to overhead other than overhead related to the Emerald Driller and Sapphire Driller will be excluded.

“ Released Amounts ” shall have the meaning set forth in the Second Amendment.

“ Second Amendment ” means the Second Amendment to Credit Agreement dated as of July 31, 2009 among the Mandated Lead Arrangers, the Lenders, the Borrowers and the Guarantors.

(cc) Article 2 of the Credit Agreement is hereby amended by deleting Sections 2.01(a)(iii) and (iv), Sections 2.01(b)(ii), (iii) and (iv), Sections 2.05(a)(iii) and (iv), and Sections 2.05(b)(ii), (iii) and (iv).

(dd) Section 2.01(c) of the Credit Agreement is hereby amended by replacing the Section in its entirety with the following:

(c) Revolving Advances . Each Lender severally agrees, on the terms and conditions set forth in this Agreement, to make Revolving Advances to any Borrower from time-to-time on any Business Day during the period from the Rig 1 Delivery Date until the Final Maturity Date in a maximum amount up to but not to exceed at any time outstanding its Revolving Commitment; provided however that the aggregate outstanding principal amount of the sum of (i) all Revolving Advances plus (ii) the Letter of Credit Exposure shall not exceed at any time $10,000,000. Each Revolving Borrowing shall be in an aggregate amount not less than $1,000,000 and in integral multiples thereof. Within the limits of each Lender’s Revolving Commitment, the Borrowers may from time-to-time borrow, prepay pursuant to Section 2.07(b) and reborrow under this Section 2.01(c) .

(ee) Section 2.03(a) of the Credit Agreement is hereby amended by deleting the last sentence of the Section in its entirety.

(ff) Section 2.07(c) of the Credit Agreement is hereby amended by inserting the following clause (vii):

(vii) Second Amendment Mandatory Prepayment . On or before the earlier of (i) August 24, 2009, and (ii) the receipt by the Parent or any of its Affiliates of proceeds from a Debt issuance or offering of Equity Interests by the Parent or any of its Subsidiaries, the Top-Up Tranche 1 Advances shall be prepaid in an amount equal to $6,900,000. Such prepayment shall be made from amounts then on deposit in the Debt Service Reserve Account of Borrower 2, to the extent the amounts on deposit therein exceed 3 months of Debt Service of Borrower 2 as

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of such date ( provided , that the full amount of such prepayment shall be due and payable regardless of whether the balance of Borrower 2’s Debt Service Reserve Account is sufficient therefor) and shall be applied in accordance with Section 2.07(c)(vi) . For the avoidance of doubt, no prepayment premium shall be due under Section 2.07(d) in connection with such prepayment.

(gg) Section 2.07(d) of the Credit Agreement is hereby amended by replacing the chart following clause (iii) thereof in its entirety with the following:

(hh) Section 2.14(a)(ii) of the Credit Agreement is hereby amended by replacing the Section in its entirety with the following:

(ii) if such issuance, increase, or extension would cause the Letter of Credit Exposure to exceed an amount equal to $10,000,000 minus the sum of the aggregate outstanding principal amount of all Revolving Advances;

(ii) Sections 3.02(d) and (e) of the Credit Agreement are hereby amended by deleting all references to Tranche 3 and Tranche 4 therefrom.

(jj) Article 3 of the Credit Agreement is hereby amended by deleting Sections 3.02(f) and (g) and Sections 3.03(f), (g) and (h).

(kk) Section 3.04 of the Credit Agreement is hereby amended by replacing the Section in its entirety with the following:

Section 3.04 Conditions Precedent to Revolving Borrowings . The obligation of each Lender to make each Revolving Advance as part of each Revolving Borrowing for each particular Tranche is subject to the conditions precedent that, with respect to each Tranche of Revolving Advances, the applicable Borrower shall have complied with the requirements of Section 5.14 and 5.15 .

(ll) Section 4.10 of the Credit Agreement is hereby amended by replacing the Section in its entirety with the following:

Section 4.10 Subsidiaries; Corporate Structure . Schedule 4.10 sets forth as of the effective date of the Second Amendment a list of all Subsidiaries of the Parent and, as to each such Subsidiary, the jurisdiction of formation, the outstanding Equity Interests therein, and the owner thereof. The Equity Interests indicated to

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be owned by the Person on Schedule 4.10 are fully paid and non-assessable and are owned by the persons indicated on such Schedule, free and clear of all Liens other than Permitted Liens and Liens granted by Excluded Entities.

(mm) Article IV of the Credit Agreement is hereby amended by inserting the following Section 4.23 in appropriate numerical order:

Section 4.23 Earnings Account . Amounts deposited into each Earnings Account will be utilized only as permitted under this Agreement.

(nn) Section 5.04(b)(ii) and Section 5.04(c) of the Credit Agreement are hereby amended by deleting all references to Tranche 3 Commitments and Tranche 4 Commitments.

(oo) Section 5.06(d) of the Credit Agreement is hereby amended by replacing the Section in its entirety with the following:

(d) Excess Cash Flow Certificate . (i) As soon as available and in any event not later than 45 days after the end of each fiscal quarter of each Borrower, a duly completed Excess Cash Flow Certificate with respect to each Borrower signed by a Responsible Officer of the Parent; and (ii) on or before August 24, 2009, a duly completed roll-forward to July 31, 2009, of the Excess Cash Flow Certificate delivered to the Lenders on July 22, 2009, in form and substance reasonably acceptable to the Lenders.

(pp) Section 5.06 of the Credit Agreement is hereby amended by renumbering Section 5.06(n) as Section 5.06(o) and inserting the following new Section 5.06(n) in appropriate alphabetical order:

(n) Weekly Updates . An update of the cash position and related forecast of the Parent and of each Borrower to be provided (i) prior to the making of the prepayment required under Section 2.07(c)(vii) , weekly; and (ii) thereafter, on a bi-weekly basis if required by any Lender.

(qq) Section 5.09(b) of the Credit Agreement is hereby amended by replacing the Section in its entirety with the following:

(b) Use the proceeds of the Tranche 1 Top-Up Advances for payment of expenses and obligations related to Rig 1 or Rig 2 or general corporate purposes (other than payment of expenses and obligations related to Rig 3, Rig 4, or any drillship).

(rr) Section 5.14(b)(ii) of the Credit Agreement is hereby amended by replacing the Section in its entirety with the following:

(ii) Retention Account . The applicable Borrower shall establish an interest bearing account subject to an Account Control Agreement with the Collateral Agent (such account, the “ Retention Account ”) into which each Borrower will transfer promptly upon, and in any event within 1 Business Day of,

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receipt in the applicable Earnings Account of any payment under a drilling contract or otherwise with respect to the operation of a Rig, the amount of such payment, less an amount equal to the sum of (a) Permitted Operating Expenses for the applicable Borrower and Rig for the days for which such revenues were received, as certified by such Borrower in detail reasonably acceptable to the Facility Agent, (b) Permitted Overhead Expenses attributable to the applicable Borrower and Rig for the days for which such revenues were received, as certified by such Borrower in detail reasonably acceptable to the Facility Agent and (c) any amount needed to cause the Retained Amount (as defined in Section 7.06(a) ) to remain in the applicable Earnings Account to the extent such amount is (and will be on the next Payment Date, as determined by the Facility Agent) available at the appropriate level in the cash flow waterfall, to be held pending the next Payment Date or other applicable payment date provided by this Agreement and application pursuant to Section 7.06 .

(ss) Section 6.02(b) and (c) of the Credit Agreement are hereby amended by replacing the Sections in their entirety with the following:

(b) unsecured Debt owing by any Loan Party (other than the Parent) to the Parent or any other Loan Party (other than a Borrower), and unsecured loans of Released Amounts owing by the Parent to the Borrowers; provided that, in each case (i) such Debt shall constitute Collateral under the Security Agreement, (ii) be on terms (including subordination terms) acceptable to the Facility Agent and (iii) be otherwise permitted under the provisions of Section 6.05 ;

(c) Guarantees of any Loan Party (other than a Borrower) in respect of Debt otherwise permitted hereunder of any Loan Party (other than the Parent);

(tt) Section 6.02 of the Credit Agreement is hereby further amended by inserting the following clause (p):

(p) Guarantees of the Parent of Debt of Excluded Entities and of other performance or payment obligations of Excluded Entities incurred in the ordinary course of business, including without limitation obligations of P2020 Rig Co and P2021 Rig Co under the rig construction contracts for Rig 3 and Rig 4 and the financings with r