Table of Contents

  **UNITED STATES SECURITIES AND EXCHANGE COMMISSION****Washington, D.C. 20549****Form 8-K****CURRENT REPORT****Pursuant to Section 13 or 15(d) of theSecurities Exchange Act of 1934****Date of Report *(Date of earliest event reported)*: June 11, 2007****Cal Dive International, Inc.***(Exact name of registrant as specified in its charter)*     **Delaware** **001-33206** **61-1500501***(State or other jurisdiction of incorporation)* *(Commission File Number)* *(IRS Employer Identification No.)*     **400 North Sam Houston Parkway, E., Suite 1000**    **Houston, Texas**   **77060***(Address of principal executive offices)*   *(Zip Code)***(281) 618-0400***(Registrant’s telephone number, including area code)*Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy thefiling obligations of the registrant under any of the following:þ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)þ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17CFR 240.14d-2(b))o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17CFR 240.13e-4(c))  
 

**TABLE OF CONTENTS**
Item 1.01 Entry into a Material Definitive AgreementItem 8.01 Other EventsItem 9.01 Financial Statements and ExhibitsSIGNATURESIndex to ExhibitsAgreement and Plan of MergerPress ReleaseConference Call Presentation

Table of Contents
**Item 1.01 Entry into a Material Definitive Agreement.**On June 11, 2007, Cal Dive International, Inc. (“Cal Dive”) and Horizon Offshore, Inc. (“Horizon”)issued a joint press release announcing that they have signed a definitive agreement (the “MergerAgreement”) under which Horizon will merge into Cal Dive Acquisition LLC, a wholly-owned subsidiaryof Cal Dive, in exchange for cash and common stock of Cal Dive. As a result, Horizon will become awholly-owned subsidiary of Cal Dive.Under the terms of the Merger Agreement, Horizon stockholders will receive in the merger acombination of 0.625 shares of Cal Dive common stock and $9.25 in cash for each share of Horizoncommon stock outstanding, or an estimated total of 20.4 million Cal Dive shares and $302.5 millionin cash. Based on Cal Dive’s closing stock price on Monday, June 11, 2007, this equates to atransaction value of approximately $19.25 per Horizon share, which represents premiums ofapproximately 14% to Horizon’s closing price on Monday, June 11, 2007, and approximately 18% toHorizon’s 30-day average trading price.It is expected that the transaction will be tax free to Horizon and the stock portion of theconsideration will be received tax free by its stockholders. Upon completion of the transaction,it is anticipated that Horizon stockholders will own approximately 20% of the common stock of CalDive compared to approximately 80% owned by existing Cal Dive stockholders. It is furtheranticipated that Helix Energy Solutions Group, Inc., Cal Dive’s majority stockholder, will ownapproximately 59% of the combined company, compared to its current ownership of approximately 73%of Cal Dive.The cash portion of the transaction will be funded through a $675 million commitment from Bank ofAmerica, consisting of a $375 million senior secured term loan and a $300 million senior securedrevolving credit facility. There is no financing condition to consummation of the transaction.Following the transaction, Cal Dive believes its strong cash flow from operations will allow it toreduce its net debt, fully fund its current capital program and pursue future growth initiatives.The limited amortization payments and prepayable nature of the term loan provide Cal Divesignificant financial flexibility. In connection with this transaction, Banc of America SecuritiesLLC and J.P. Morgan Securities Inc. have terminated an equity lockup agreement that was scheduledto expire on June 12, 2007.The acquisition is conditioned upon, among other things, the approval of Horizon stockholders, thetermination or expiration of the waiting period under the Hart-Scott-Rodino Antitrust ImprovementsAct of 1976 and other customary regulatory approvals. The transaction is expected to be completedin the third quarter of 2007.Cal Dive is currently a subcontractor providing manned diving services to Horizon and its ultimatecustomers. For 2006 and the first quarter of 2007, amounts paid by Horizon to Cal Dive for suchservices were approximately $16.2 million and $4.1 million, respectively.The foregoing summary is not intended to be complete and is qualified in its entirety by the fulltext of the Merger Agreement, a copy of which is filed as Exhibit 2.1 to this Current Report onForm 8-K and incorporated by reference herein.
 

Table of Contents
**Item 8.01 Other Events.**On June 11, 2007, Cal Dive issued a press release announcing the execution of the Merger Agreement.A copy of the press release is attached hereto as Exhibit 99.1 and incorporated herein byreference. Also on June 11, 2007, Cal Dive posted to its website presentation materials for use byinvestors in connection with Cal Dive’s teleconference and webcast on June 12, 2007 relating to itsproposed business combination with Horizon. A copy of such presentation materials is attachedhereto as Exhibit 99.2 and incorporated herein by reference.**Important Additional Information will be filed with the SEC**In connection with the proposed merger, Cal Dive will file a Registration Statement on Form S-4,Horizon will file a proxy statement, and Cal Dive will file an information statement and bothcompanies will file other relevant documents concerning the proposed merger with the SEC.Investors and securities holders of both companies are urged to read the Form S-4, proxy statementand information statement when they become available because those documents will contain importantinformation about the proposed merger. The definitive proxy statement will be mailed to Horizonstockholders, and the definitive information statement will be mailed to Cal Dive stockholders.Investors and security holders may obtain a copy of such documents free of charge from the SEC’swebsite at www.sec.gov. Copies of such documents may also be obtained free of charge from CalDive’s website at www.caldive.com and Horizon’s website at www.horizonoffshore.com.**Participants in the Solicitation**Cal Dive, Horizon and their respective directors and executive officers may be deemed to beparticipants in the solicitation of proxies from Horizon’s stockholders in favor of the proposedmerger. Information regarding Cal Dive’s directors and executive officers is available in CalDive’s proxy statement for its 2007 annual meeting of stockholders, which was filed with the SEC onApril 9, 2007. Information regarding Horizon’s directors and executive officers is available inHorizon’s proxy statement for its 2007 annual meeting of stockholders, which was filed with the SECon April 24, 2007. Additional information regarding the interests of such potential participantswill be included in the proxy statement and information statement, and other relevant documentsfiled with the SEC when they become available. You can obtain free copies of these documents fromCal Dive or Horizon using the contact information above.**Item 9.01 Financial Statements and Exhibits.**  (c)      Exhibits.      2.1 Agreement and Plan of Merger, dated as of June 11, 2007 by and amongCal Dive International, Inc., Cal Dive Acquisition, LLC, and HorizonOffshore, Inc.*   99.1 Press Release issued jointly by Cal Dive International, Inc. andHorizon Offshore, Inc. dated June 11, 2007.
 

Table of Contents
   99.2 Conference Call Presentation (including reconciliations to non-GAAPfinancial information). * The schedules to the Merger Agreement have been omitted pursuant to Item 601(b)(2) of RegulationS-K. The Company will furnish supplementally a copy of any omitted schedule to the SEC uponrequest.
 

Table of Contents
**SIGNATURES**Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has dulycaused this report to be signed on its behalf by the undersigned, hereunto duly authorized.         **CAL DIVE INTERNATIONAL, INC.**         By: /s/ G. Kregg Lunsford             G. Kregg Lunsford      Executive Vice President,      Chief Financial Officer and Treasurer  Date: June 12, 2007
 

Table of Contents
Index to ExhibitsExhibits.      2.1 Agreement and Plan of Merger, dated as of June 11, 2007 by and amongCal Dive International, Inc., Cal Dive Acquisition, LLC, and HorizonOffshore, Inc.*   99.1 Press Release issued jointly by Cal Dive International, Inc. andHorizon Offshore, Inc. dated June 11, 2007.   99.2 Conference Call Presentation (including reconciliations to non-GAAPfinancial information). * The schedules to the Merger Agreement have been omitted pursuant to Item 601(b)(2) of RegulationS-K. The Company will furnish supplementally a copy of any omitted schedule to the SEC uponrequest.