EIGHTH AMENDMENT TO LOAN AGREEMENT

EXHIBIT 10.6

EIGHTH AMENDMENT TO LOAN AGREEMENT

     This EIGHTH AMENDMENT TO LOAN AGREEMENT (the “Eighth Amendment”), dated as of the 4th day of November, 2004, is made by and among HORIZON OFFSHORE CONTRACTORS, INC. (“Contractors”), HORIZON SUBSEA SERVICES, INC. (“Subsea”), and HORIZON VESSELS, INC. (“Vessels,” and together with Contractors and Subsea, the “Borrowers”), jointly and severally, each of the financial institutions which is or may from time to time become a party to such Agreement (as defined below) (collectively, “Lenders”, and each a “Lender”), and SOUTHWEST BANK OF TEXAS, N.A., as agent (in such capacity, the “Agent”).

W I T N E S S E T H:

     WHEREAS, Borrowers, Lenders and Agent are parties to that certain Loan Agreement dated as of March 26, 2001 (as the same has been or may hereafter be amended, supplemented or otherwise modified, the “Agreement”);

     WHEREAS, pursuant to the Amendment No. 1 to May Purchase Agreement attached hereto as Exhibit B, the Borrowers propose to sell approximately $9,625,000 aggregate principal amount of 18% Subordinated Secured Notes due March 31, 2007, for a purchase price of approximately $7,700,000; and

     WHEREAS, Borrowers, Lenders and Agent now desire to amend the Agreement as herein set forth.

     NOW, THEREFORE, in consideration of the foregoing recitals and the mutual covenants and premises contained herein, together with other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, and subject to the conditions to effectiveness set forth in Section 6 hereof, the parties hereto agree as follows:

     1. Terms. Capitalized terms used in this Eighth Amendment (including the recitals hereof) shall have the meanings assigned to them in the Agreement, as amended by this Eighth Amendment.

     2. Amendments.

     (a) Section 1.1 of the Agreement is hereby amended by adding the following definitions thereto in the correct alphabetical order:

“Cash Interest” means, for any period, the consolidated Interest Expense of Guarantor and its Subsidiaries for such period, determined in accordance with GAAP applied consistently, less (a) interest related to the Subordinated Debt (which is in fact paid-in-kind) and (b) all amounts included in Interest Expense, in accordance with GAAP, for amortization of debt fees, discounts and warrant expense.

“Subordinated Debt” means indebtedness of Guarantor incurred pursuant to (a) that certain Purchase Agreement dated March 11, 2004, among Guarantor, the guarantors listed therein and the purchasers listed therein, pursuant to which those certain 16% subordinated secured notes due March 31, 2007, in an aggregated principal amount equal to $65,400,000.00 were issued, as the same may be amended, supplemented or modified from time to time with the consent of Majority Lenders, and (b) that certain Purchase Agreement dated May 27, 2004, among Guarantor, the guarantors listed therein and the purchasers listed therein, pursuant to which (i) those certain 18% subordinated secured notes due March 31, 2007, in an aggregated principal amount equal to $18,750,000.00 were issued on May 27, 2004, (ii) those certain additional 18% subordinated secured notes due March 31, 2007, in an aggregated principal amount equal to $5,291,865.00 were issued on September 17, 2004 (the debt referred to in the foregoing clauses (i) and (ii) is referred to herein as the “Additional Sub Debt”), and (iii) those certain additional 18% subordinated secured notes due March 31, 2007, in an aggregated principal amount equal to $9,625,000 were issued on November 4, 2004 (the “New Additional Subordinated Debt”), as the same may be amended, supplemented or modified from time to time with the consent of Majority Lenders.

     (b) The following definitions set forth in Section 1.1 of the Agreement are hereby amended and restated in their entirety as follows:

“Borrowing Base” means, at any particular time, an amount equal to the sum of (a) eighty percent (80%) of Eligible Accounts, and (b) thirty-five percent (35%) of amounts shown as retention billings with respect to Manta Ray on the September 30, 2004, Borrowing Base Certificate, provided that (i) such amounts meet all other criteria necessary to constitute an Eligible Account, (ii) such amounts represent a final billing with respect to the contract in question and not any progress billing, and (iii) the chief financial officer of the Borrower certifies in writing to the Agent and Lenders that all contractual requirements for payment of such amounts have been met and that such amounts meet the foregoing criteria and that such amounts are not subject to any dispute, claim, offset, recoupment or any other contingency for payment or reduction in amounts payable on account of liquidated damages, claims or liens of subcontractors or otherwise. No other amounts constituting or relating to retention, whether billed or unbilled, shall be included in the Borrowing Base without the express written consent of the Lenders.

“Combined Commitments” means as to all Lenders, the obligations of Lenders to make Advances and issue Letters of Credit in an aggregate principal amount at any time outstanding up to but not exceeding $6,300,000.

“EBITDA” means for Guarantor and its Subsidiaries, on a consolidated basis, for any period, the sum of (a) Net Income before gains and losses on sales of assets (to the extent such gains and losses are included in earnings), plus (b) Tax Expense, plus (c) depreciation and amortization (including accelerated amortization of prepaid loan fees, discounts and warrant expense for the purpose of loss on debt extinguishment, in accordance with GAAP), plus (d) Interest Expense.

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“EBITDAR” means for Guarantor and its Subsidiaries, on a consolidated basis, for any period, the sum of (a) Net Income before gains and losses on sales of assets (to the extent such gains and losses are included in earnings), plus (b) Tax Expense, plus (c) depreciation and amortization (including accelerated amortization of prepaid loan fees, discounts and warrant expense for the purpose of loss on debt extinguishment, in accordance with GAAP), plus (d) Interest Expense, plus (e) restructuring charges, including costs of professional advisors to Guarantor and its Subsidiaries (including costs of professional advisors to Guarantor’s lenders and other creditors which are required to be paid by Guarantor or its Subsidiaries) not to exceed $3,250,000 for the fiscal year ending December 31, 2004.

“Fixed Charge Coverage Ratio” means for Guarantor and its Subsidiaries, on a consolidated basis, (a) as of September 30, 2004, (i) EBITDA for the quarter ended as of September 30, 2004, divided by (ii) the sum of (A) Current Maturities of Long Term Debt as of September 30, 2004 divided by four, plus (B) Cash Interest for the quarter ended September 30, 2004, plus (C) Tax Expense for the quarter ended as of September 30, 2004, and (b) as of December 31, 2004, (i) EBITDA for the quarters ended as of September 30, 2004 and December 31, 2004, divided by (ii) the sum of (A) Current Maturities of Long Term Debt as of December 31, 2004 divided by two, plus (B) Cash Interest for the quarters ended as of September 30, 2004 and December 31, 2004, plus (C) Tax Expense for the quarters ended as of September 30, 2004 and December 31, 2004.

“Tangible Net Worth” means, at any particular date, all amounts which, in conformity with GAAP, would be included as stockholder’s equity on a consolidated balance sheet of Guarantor and its Subsidiaries, including without limitation adjustments for the addition of paid-in-kind interest, discounts and warrant amortization on Subordinated Debt; provided, however, there shall be excluded therefrom (a) any amount at which shares of capital stock of Guarantor or any Subsidiary appear as an asset on Guarantor’s or such Subsidiary’s balance sheet, (b) goodwill, including any amounts, however designated, that represent the excess of the purchase price paid for assets or stock over the value assigned thereto, (c) patents, trademarks, trade names, and copyrights, (d) loans and advances to any stockholder, director, officer, or employee of Guarantor or any Subsidiary or any Affiliate, and (e) all other assets which are properly classified as intangible assets.

“Total Funded Debt” means, for Guarantor and its Subsidiaries, on a consolidated basis, the sum of (a) all indebtedness for borrowed money, whether or not evidenced by notes, bonds, debentures, notes or similar instruments, (b) all Capital Lease Obligations, (c) all obligations to pay the deferred purchase price of property or services (but excluding trade accounts payable or trade notes in the ordinary course of business), (d) all indebtedness secured by a Lien on the property of Guarantor or any of its Subsidiaries, and (e) all letter of credit liabilities (including the Letter of Credit Liabilities).

     (c) The definition of Eligible Accounts set forth in Section 1.1 of the Agreement is hereby amended to add the following sentence at the end thereof:

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“For purposes of calculating Eligible Accounts, amounts related to retention shall include any amounts that previously constituted retention whether billed or unbilled and, therefore, shall not constitute Eligible Accounts.”

     (d) Section 8.1(d) of the Agreement is hereby amended and restated in its entirety as follows:

“(d) letter of credit, performance and bid bonds obtained by Borrowers in the ordinary course of their business, other than the Letters of Credit, up to an aggregate amount of $33,545,000.00 at any time;”

     (e) Section 10.1(a) of the Agreement is hereby amended and restated to read in its entirety as follows:

“(a) Any Borrower shall default in the payment or prepayment when due of any principal or interest on the Obligations or any portion thereof, or shall default in the payment or prepayment when due of any fees or other amounts payable by any of them under this Agreement or under any other Loan Documents and, in respect of fees or other amounts only, such default shall continue for three (3) Business Days after such amount is due.”

     (f) Section 10.1(o) of the Agreement is hereby amended and restated to read in its entirety as follows:

“(o) Guarantor (or any Borrower or any Subsidiary) pays any principal, interest or fees on (1) the New Subordinated Debt in cash, except for cash payments of principal of the New Subordinated Debt which are paid from (i) the proceeds of Pemex Contract EPC-64 or the Williams Contract, or (ii) the proceeds of the issuance of equity at any time after March 1, 2004, (2) the Additional Sub Debt or the New Additional Subordinated Debt in cash, except for cash payments of principal or interest of the Additional Sub Debt or the New Additional Subordinated Debt to the extent expressly permitted pursuant to that certain Collateral Sharing Agreement dated October 29, 2004 and that certain Consent Letter dated May 25, 2004, or (3) any other Subordinated Debt in cash, except to the extent of proceeds of collateral securing the same to the extent the Liens with respect to such collateral are expressly permitted hereunder or under any Lender consent and subject to any priority of Lenders in respect of such collateral.”

     (g) Section 10.1 of the Agreement is hereby amended to insert the following subsection (p) thereto:

“(p) Any document or instrument evidencing any Subordinated Debt shall be amended or modified without the prior written consent of the Majority Lenders.”

     3. Consent. The Agent and the Lenders hereby consent to (a) the issuance of the New Additional Subordinated Debt pursuant to that certain Amendment No. 1 to May Purchase Agreement dated November 4, 2004 and attached as Exhibit B hereto, (b) the issuance of Series A Redeemable Participating Preferred Stock pursuant to the documents attached hereto as Exhibit C provided that any cash redemption rights with respect thereto are subordinated to the Obligations as provided in that certain Subordination Agreement of even date herewith among

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Agent and the Subordinate Parties listed on the signature pages thereto, and (c) the recapitalization of the subordinated debt on terms consistent in all material respects with Section 11 of the draft investment proposal dated October 21, 2004, and attached hereto as Exhibit A and any change of control with respect to Parent in connection therewith provided further that (i) the terms of any new Subordinated Debt contemplated thereby (A) has subordination provisions no less favorable to Lenders than the existing terms of subordination of the New Subordinated Debt, (B) is not secured by any collateral other than collateral permitted to secure the New Subordinated Debt, (C) does not have a maturity date or any mandatory payment, prepayment, redemption or defeasance provisions with respect to interest or principal requiring any payment, redemption or defeasance prior to January 21, 2005, except for permitted payments of interest or principal from proceeds of Collateral permitted to secure the same and (D) does not provide for the set aside of any funds for any payment, prepayment, redemption or defeasance of any portion thereof, (ii) there are no commitment fees, underwriting fees or similar fees (other than reimbursements for actual out-of-pocket third party fees and expenses) payable to the holders of any Subordinated Debt or any Affiliate thereof in connection with the recapitalization other than those payable solely in the form of common stock of Parent, (iii) there occurs no change of control as a result thereof with respect to any Borrower or any other Guarantor other than as a result of the issuance of equity in Parent, (iv) there are no management agreements, servicing agreements or similar agreements providing for the payment of any cash management fees, servicing fees, or similar fees to any Affiliate in connection therewith by Borrowers or any Guarantor, (iv) there are no mandatory redemption rights with respect to any capital stock issued in connection with such recapitalization, and (v) there are no covenants placed on the Borrowers or any Guarantor in connection therewith that would restrict the ability of any such party to grant Liens on its assets or to pay and perform their respective Obligations in accordance with the terms of the Loan Documents. This consent is a limited, one-time consent with respect to the matters set forth herein and shall not create any obligation of Agent or Lenders to consent to, or be deemed a consent to, any other matter not expressly contemplated hereby. Reference to the Proposal for purposes of this Section 3 shall not be deemed to be a consent to or agreement of the Agent or Lenders to any other matters not expressly set forth herein, including, without limitation, any extension of the Termination Date or the making of any restricted payment or the payment of any amounts in respect of debt which are not permitted under the Loan Documents. This Eighth Amendment and the consents in this Section 3 shall not create any implicit agreement of the Agent or Lenders to agree to any extension of the Termination Date.

     4. Waiver. The Borrowers submitted a Borrowing Base Certificate dated June 30, 2004, which contained receivables payable in excess of 30 days from invoice date and retention under a contract with Taylor Energy Company as part of receivables under the Borrowing Base. The Borrowers have not acknowledged that the submission of such Borrowing Base Certificate constitutes an Event of Default under the Agreement. The Borrower submitted a revised Borrowing Base Certificate upon learning of the issue of the inclusion of such Taylor Energy Company receivables in the Borrowing Base. Agent and Lenders hereby waive any Unmatured Event of Default or any Event of Default, if any, that may have occurred under the Agreement as a result thereof, subject to the terms and conditions contained herein. The Agent and Lenders have no actual knowledge of any other Event of Default or Unmatured Event of Default disputed by the Borrowers, or otherwise in existence as of the date hereof.

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     5. Advances. Notwithstanding anything to the contrary contained in the Agreement, from and after the date hereof the Borrowers shall have no right to receive any further Advances under the Agreement. Furthermore, the Lenders shall not be required to issue any new Letters of Credit or increase any existing Letters of Credit under the Agreement. Any payments received by Lenders on the Obligations shall automatically reduce the line of credit provided under the Agreement by the principal amount thereof and the Combined Commitments amount shall be reduced accordingly. A reduction of the Combined Commitments pursuant to this Section 5 shall reduce each Lender’s Commitment pro rata.

     6. Conditions Precedent. The effectiveness of this Eighth Amendment is subject to the satisfaction of the following:

     (a) this Eighth Amendment shall have been duly executed and delivered by each of the parties set forth on the signature pages hereto;

     (b) the transactions contemplated by the Proposal in connection with the issuance of Subordinated Debt shall have been consummated to the satisfaction of Agent and Lenders and Agent shall have received satisfactory evidence that the Borrowers have received in immediately available U.S. Dollars not less than $7,700,000 in connection therewith;

     (c) Agent and Lenders shall have received such other documents, instruments and agreements as they may require to evidence the closing and funding of the transaction contemplated in connection with the issuance of Subordinated Debt under the Proposal;

     (d) Agent shall have received evidence satisfactory to it that the conditions precedent to effectiveness of the Seventh Amendment to the Foreign Loan Agreement shall have been satisfied; and

     (e) all fees and expenses of Vinson & Elkins, LLP, as counsel to Agent, and all other professional fees of Agent’s consultants, in each case incurred in connection with the Agreement and this Eighth Amendment, shall have been paid in full.

     7. Release and Covenant Not to Sue. EACH BORROWER (IN ITS OWN RIGHT AND ON BEHALF OF ITS DIRECTORS, OFFICERS, EMPLOYEES, INDEPENDENT CONTRACTORS, ATTORNEYS AND AGENTS) AND EACH OF THE GUARANTOR AND THE ADDITIONAL GUARANTORS (IN ITS OWN RIGHT AND ON BEHALF OF ITS RESPECTIVE ATTORNEYS AND AGENTS) (THE “RELEASING PARTIES”) JOINTLY AND SEVERALLY RELEASE, ACQUIT, AND FOREVER DISCHARGE AGENT AND EACH LENDER AND THEIR RESPECTIVE DIRECTORS, OFFICERS, EMPLOYEES, INDEPENDENT CONTRACTORS, ATTORNEYS AND AGENTS, (COLLECTIVELY, THE “RELEASED PARTIES”), TO THE FULLEST EXTENT PERMITTED BY APPLICABLE STATE AND FEDERAL LAW, FROM ANY AND ALL ACTS AND OMISSIONS OF THE RELEASED PARTIES, AND FROM ANY AND ALL CLAIMS, CAUSES OF ACTION, COUNTERCLAIMS, DEMANDS, CONTROVERSIES, COSTS, DEBTS, SUMS OF MONEY, ACCOUNTS, RECKONINGS, BONDS, BILLS, DAMAGES, OBLIGATIONS, LIABILITIES, OBJECTIONS, AND EXECUTIONS OF ANY NATURE, TYPE, OR

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DESCRIPTION WHICH THE RELEASING PARTIES HAVE AGAINST THE RELEASED PARTIES, INCLUDING, BUT NOT LIMITED TO, NEGLIGENCE, GROSS NEGLIGENCE, USURY, FRAUD, DECEIT, MISREPRESENTATION, CONSPIRACY, UNCONSCIONABILITY, DURESS, ECONOMIC DURESS, DEFAMATION, CONTROL, INTERFERENCE WITH CONTRACTUAL AND BUSINESS RELATIONSHIPS, CONFLICTS OF INTEREST, MISUSE OF INSIDER INFORMATION, CONCEALMENT, DISCLOSURE, SECRECY, MISUSE OF COLLATERAL, WRONGFUL RELEASE OF COLLATERAL, FAILURE TO INSPECT, ENVIRONMENTAL DUE DILIGENCE, NEGLIGENT LOAN PROCESSING AND ADMINISTRATION, WRONGFUL SETOFF, VIOLATIONS OF STATUTES AND REGULATIONS OF GOVERNMENTAL ENTITIES, INSTRUMENTALITIES AND AGENCIES (BOTH CIVIL AND CRIMINAL), RACKETEERING ACTIVITIES, SECURITIES AND ANTITRUST LAWS VIOLATIONS, TYING ARRANGEMENTS, DECEPTIVE TRADE PRACTICES, BREACH OR ABUSE OF ANY ALLEGED FIDUCIARY DUTY, BREACH OF ANY ALLEGED SPECIAL RELATIONSHIP, COURSE OF CONDUCT OR DEALING, ALLEGED OBLIGATION OF FAIR DEALING, ALLEGED OBLIGATION OF GOOD FAITH, AND ALLEGED OBLIGATION OF GOOD FAITH AND FAIR DEALING, WHETHER OR NOT IN CONNECTION WITH OR RELATED TO THE AGREEMENT, THE LOAN DOCUMENTS AND THIS EIGHTH AMENDMENT, AT LAW OR IN EQUITY, IN CONTRACT IN TORT, OR OTHERWISE, KNOWN OR UNKNOWN, SUSPECTED OR UNSUSPECTED (COLLECTIVELY, THE “RELEASED CLAIMS”). THE RELEASING PARTIES FURTHER JOINTLY AND SEVERALLY AGREE TO LIMIT ANY DAMAGES THEY MAY SEEK IN CONNECTION WITH ANY CLAIM OR CAUSE OF ACTION, IF ANY, TO EXCLUDE ALL PUNITIVE AND EXEMPLARY DAMAGES, DAMAGES ATTRIBUTABLE TO LOST PROFITS OR OPPORTUNITY, AND THE RELEASING PARTIES DO HEREBY JOINTLY AND SEVERALLY WAIVE AND RELEASE ALL SUCH DAMAGES WITH RESPECT TO ANY AND ALL CLAIMS OR CAUSES OF ACTION WHICH MAY ARISE AT ANY TIME AGAINST ANY OF THE RELEASED PARTIES. THE RELEASING PARTIES REPRESENT AND WARRANT THAT NO FACTS EXIST WHICH COULD PRESENTLY SUPPORT THE ASSERTION OF ANY OF THE RELEASED CLAIMS AGAINST THE RELEASED PARTIES. THE RELEASING PARTIES FURTHER COVENANT NOT TO SUE THE RELEASED PARTIES ON ACCOUNT OF ANY OF THE RELEASED CLAIMS, AND EXPRESSLY WAIVE ANY AND ALL DEFENSES THEY MAY HAVE IN CONNECTION WITH THEIR DEBTS AND OBLIGATIONS UNDER THE AGREEMENT, THE LOAN DOCUMENTS AND THIS EIGHTH AMENDMENT. THIS SECTION 7 IS IN ADDITION TO AND SHALL NOT IN ANY WAY LIMIT ANY OTHER RELEASE, COVENANT NOT TO SUE, OR WAIVER BY THE RELEASING PARTIES IN FAVOR OF THE RELEASED PARTIES. NOTWITHSTANDING ANY PROVISION OF THE AGREEMENT, THIS EIGHTH AMENDMENT OR ANY OTHER LOAN DOCUMENT, THIS SECTION 7 SHALL REMAIN IN FULL FORCE AND EFFECT AND SHALL SURVIVE THE DELIVERY AND PAYMENT ON THE OBLIGATIONS, THE AGREEMENT, THIS EIGHTH AMENDMENT AND THE OTHER LOAN DOCUMENTS.

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     8. Reaffirmation of Guarantees. By their execution hereof, each of the Guarantor and the Additional Guarantors acknowledges and agrees (a) to the terms of the release and covenant not to sue set forth in the foregoing Section 7, and (b) that all of the terms and provisions of their respective guarantees shall remain in full force and effect and that the amendments and modifications herein contained shall in no manner adversely affect or impair the Guarantor’s or any Additional Guarantor’s obligations under such guaranty.

     9. Binding Effect. It is further understood and agreed by and among the parties hereto that all terms and conditions of the Agreement, except as herein modified, shall remain in full force and effect.

     10. Counterparts. This Eighth Amendment may be executed in multiple counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument.

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     IN WITNESS WHEREOF, the parties hereto have caused this Eighth Amendment to be duly executed as of the day and year first above written.

[Signatures continued on next page.]

SIGNATURE PAGE - 1

SIGNATURE PAGE - 2

Acknowledged and Agreed to this 4th day of November, 2004.

HORIZON OFFSHORE, INC.
PROGRESSIVE PIPELINE CONTRACTORS, INC.
AFFILIATED MARINE CONTRACTORS, INC.
TEXAS OFFSHORE CONTRACTORS CORP
FLEET PIPELINE SERVICES, INC.
GULF OFFSHORE CONSTRUCTION, INC.
BAYOU MARINE CONTRACTORS, INC.
HOC OFFSHORE, S. DE R.L. DE C.V.
PT ARMANDI PRANAUPAYA
ECH OFFSHORE, S. DE R.L. DE C.V.
HORIZON OFFSHORE NIGERIA LTD.
HORIZON C-BAY COSTA AFUERA, S. DE R.L. DE C.V.
HORIZON OFFSHORE PTE. LTD.
HORIZON OFFSHORE CONTRACTORS (MAURITIUS) LTD.
HORIZON MARINE CONSTRUCTION (MAURITIUS) LTD.
TIBURON INGENIERIA Y CONSTRUCCION, S. DE R.L. DE C.V.
HORIZON VESSELS INTERNATIONAL LTD.
HORIZON OFFSHORE INTERNATIONAL LTD.
HORIZON MARINE CONSTRUCTION LTD.
HORIZON GROUP L.D.C.
PT HORIZON INDONESIA
HORIZON OFFSHORE CONTRACTORS LTD.
HORIZON MARINE CONTRACTORS (MALASIA) SDN BHD
HORIZON OFFSHORE SERVICES, LTD.
MARINE LEASING (LABUAN) PTE LTD.

ECH OFFSHORE, S. DE R.L. DE C.V.

SIGNATURE PAGE - 3

EXHIBIT A

PROPOSAL

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A-1

EXHIBIT B

AMENDMENT NO. 1 TO MAY PURCHASE AGREEMENT

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B-1

EXHIBIT C

DOCUMENTS EVIDENCING SERIES A REDEEMABLE PARTICIPATING PREFERRED STOCK

C-1