<PAGE>

                                                   [HORIZON OFFSHORE, INC. LOGO]

                              HORIZON OFFSHORE, INC

                       CODE OF ETHICS AND BUSINESS CONDUCT


Approved by Board of Directors - Dec 3, 2003
<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                   SETTING THE TONE - INTRODUCTORY INFORMATION

This Code of Ethics and Business Conduct (this "Code") sets forth the guiding
principles and policies that govern the activities of Horizon Offshore, Inc. and
its subsidiaries (collectively, "Horizon" or the "Company"). The purpose of the
Code is to set forth the Company's commitment to high ethical standards and to
reinforce prompt and consistent actions in the maintenance of those standards.
The Company expects all directors, officers and employees, by virtue of their
association or employment with the Company, to adhere to the highest standards
of personal and professional integrity and to comply with this Code and all
applicable laws, rules and regulations.

This Code is intended to promote the following objectives:

     -    Honest and ethical conduct, including the ethical handling of actual
          or apparent conflicts of interest between personal and professional
          relationships;

     -    Full, fair, accurate, timely and understandable disclosure in reports
          and documents that the Company files with, or submits to, the
          Securities and Exchange Commission and in other public communications
          made by the Company;

     -    Compliance with applicable governmental laws, rules and regulations;

     -    The prompt internal reporting of violations of the Code to the
          appropriate person or persons, as identified in the Code; and

     -    Accountability for adherence to the Code.

This Code explains the basic principles of ethics and business conduct for the
Company. No code or policy can anticipate every situation a director, officer or
employee might confront. Accordingly, this Code is intended to serve as a source
of guiding principles for directors, officers and employees, who are expected to
apply such principles to their day-to-day activities and seek advice whenever
they are unsure about a particular situation.

When in doubt about what to do, ask yourself this question:

WOULD I BE PROUD TO EXPLAIN MY ACTIONS TO MY FAMILY OR FELLOW EMPLOYEES -- OR TO
        MILLIONS OF PEOPLE AROUND THE WORLD ON TONIGHT'S NEWS BROADCAST?

If questions arise or the best course of action isn't clear, employees should
consult with their supervisors or managers. Directors or officers should consult
with the Company's General Counsel.

ACCOUNTABILITY

Each director, officer and employee must be alert and sensitive to situations
that could result in illegal, unethical or otherwise improper actions, either by
him or herself or other persons. A failure of any director, officer or employee
to comply with any law, rule or regulation, this Code, or any other applicable
Company policy may result in disciplinary action, removal or dismissal, and, if
warranted, legal proceedings against him or her on behalf of the Company.

Approved by Board of Directors - Dec 3, 2003


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                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                   SETTING THE TONE - INTRODUCTORY INFORMATION

No violation of this Code, any other Company policy, or any law, rule or
regulation will be justified by a claim that it was ordered by someone in higher
authority. No one, regardless of his or her position, is authorized to direct
another to commit an illegal act. Reporting a known or suspected violation of
this Code or any applicable law, rule, regulation or Company policy should not
be considered an act of disloyalty, but an action that shows a sense of
responsibility that will help safeguard the reputation of the Company and its
employees.

REPORTING ILLEGAL OR UNETHICAL BEHAVIOR OR VIOLATIONS OF THE CODE

You can learn more about reporting known or suspected illegal or unethical
behavior or violations of the Code by referring to Appendix A: "How to Ask
Questions or Report Violations; Enforcement."

DIRECTOR AND OFFICER RESPONSIBILITIES

The Company's directors and officers are expected to comply with this Code,
other applicable Company policies, and all applicable laws rules and
regulations. They are also expected to promote ethical behavior by (i)
encouraging employees to talk to supervisors and other appropriate personnel
when in doubt about the best course of action in a particular situation; (ii)
encouraging employees to report violations of laws, this Code or any other
Company policy to appropriate personnel; and (iii) reminding employees that the
Company will not permit retaliation for reports made in good faith.

Company directors and officers who become aware of violations of law, this Code
or any other Company policy are expected to stop the violations and, if
necessary, conduct an investigation with assistance of Company counsel if
appropriate.

PROTECTION FOR PERSONS REPORTING QUESTIONABLE BEHAVIOR

All directors, officers and employees are required to cooperate fully in any
internal investigation. If a director, officer or employee discovers the need to
report a suspected violation of law, this Code, or any Company policy, that
person will not be terminated, disciplined, demoted or otherwise discriminated
against for (i) making a report of a violation or suspected violation in good
faith and on the basis of a reasonable belief that a violation has occurred or
will occur or (ii) assisting with any ensuing investigation. To the extent
permissible, the Company will endeavor to keep confidential the identity of
anyone reporting possible violations.

AMENDMENT, MODIFICATION AND WAIVER

This Code may be amended or modified by the Company's Board of Directors. Any
waiver of the provisions of this Code for the benefit of senior financial
officers, executive officers or members of the Board of Directors requires the
review of the Audit Committee of the Company's Board of Directors and approval
by the full Board and must be promptly disclosed to shareholders in accordance
with law and the applicable rules of the Nasdaq Stock Market, Inc. Any waiver of
the Code for the benefit of an employee requires the review and approval of the
CEO. Waivers may be granted only as permitted by law and in extraordinary
circumstances.

Approved by Board of Directors - Dec 3, 2003


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<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                   SETTING THE TONE - INTRODUCTORY INFORMATION

OTHER COMPANY POLICIES

This Code outlines the general standards of ethics and business conduct that are
expected of Horizon's directors, officers and employees. Certain topics
addressed by this Code, for example insider trading and workplace safety, are
also the subject of specific Company policies that provide additional guidance
and set forth additional responsibilities and expectations. In general, the
specific requirements contained in those policies supercede the broad-based
requirements of this Code.

ACKNOWLEDGEMENT

Each director, officer and employee is expected to read and understand Horizon's
Code of Ethics and Business Conduct. On an annual basis, Horizon's General
Counsel will circulate to certain employees the form included as Appendix B to
the Code. The employee is required to return the signed and dated form to the
General Counsel.

--------------------------------------------------------------------------------
Horizon's Code of Ethics and Business Conduct is a statement of the fundamental
principles and key policies and procedures that govern the conduct of Horizon's
business. It is not intended to and does not, in any way, constitute an
employment contract or an assurance of continued employment or create any rights
in favor of any employee, client, supplier, competitor, shareholder or any other
person or entity. Horizon reserves the right to amend this Code at any time and
for any reason, and any such amendment will be disclosed as and to the extent
required by law and regulation.

Approved by Board of Directors - Dec 3, 2003


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                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                                TABLE OF CONTENTS

                                                                        PAGE #
                                                                        ------
SECTION 1  CONFLICTS OF INTEREST.....................................      5

SECTION 2  FAIR COMPETITION  - ANTITRUST LAWS........................      7

SECTION 3  BRIBERY, KICKBACKS AND OTHER IMPROPER PAYMENTS............      8

SECTION 4  GIFTS, MEALS, SERVICES AND ENTERTAINMENT..................      9

SECTION 5  INTERNATIONAL ETHICS AND COMPLIANCE.......................     10

SECTION 6  CONTRACT AUTHORIZATION....................................     12

SECTION 7  CONFIDENTIAL INFORMATION..................................     13

SECTION 8  SAFEGUARDING COMPANY ASSETS...............................     14

SECTION 9  ACCURACY OF BOOKS AND RECORDS/RECORD RETENTION............     15

SECTION 10 INSIDER TRADING...........................................     17

SECTION 11 PUBLIC COMMUNICATIONS.....................................     19

SECTION 12 EQUAL EMPLOYMENT OPPORTUNITY..............................     20

SECTION 13 HARASSMENT IN THE WORKPLACE...............................     21

SECTION 14 HEALTH, SAFETY AND THE ENVIRONMENT........................     22

SECTION 15 INFORMATION AND INFORMATION RESOURCES.....................     23

SECTION 16 LAWS, RULES AND REGULATIONS...............................     24

APPENDIX A HOW TO ASK QUESTIONS OR REPORT VIOLATIONS; ENFORCEMENT....     25

APPENDIX B ACKNOWLEDGEMENT FORM......................................     29

Approved by Board of Directors - Dec 3, 2003


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<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                        SECTION 1: CONFLICTS OF INTEREST

All directors, officers and employees of the Company are required to avoid any
situation that would create a conflict, or gives the appearance of a conflict,
between their own interests and the interests of the Company. A "conflict of
interest" exists whenever an individual's private interests interfere or
conflict in any way with the interests of the Company.

Conflicts of interest may arise when:

     -    You or someone with a close relationship to you has an interest in a
          company with which Horizon does business;

     -    You or someone with a close relationship to you receives improper
          personal benefits as a result of your position at Horizon;

     -    Other employment (including self-employment) or serving as an officer,
          director, partner or consultant for another organization interferes
          with your ability to act in the best interests of Horizon, requires
          you to use or disclose sensitive information about Horizon, or creates
          the appearance of impropriety; or

     -    You or someone with a close relationship to you receives a loan or
          other extension of credit or credit support (such as a guaranty) from
          Horizon. Horizon is prohibited by law from extending or arranging for
          the extension of personal loans to executive officers.

OUR RESPONSIBILITIES

Conflicts of interest may not always be clear-cut, so if a question arises, an
employee should consult with his or her supervisor or superior. Directors and
officers should consult with the Company's General Counsel.

Generally, directors, officers and employees are expected to:

     -    Be able to identify potential conflicts of interest when they arise;

     -    Notify appropriate personnel if they are in a situation where their
          objectivity may be questioned;

     -    Make certain that any second jobs, financial interests or management
          interests in another company do not cause a conflict of interest or
          have a negative impact on the confidence the public has in Horizon;

     -    In the case of an executive officer or manager, get approval from
          Horizon's Audit Committee and, in the case of all other company
          personnel, get approval from the Company's CEO when a company in which
          they or their family member owns or acquires an interest that is
          greater than 5 percent seeks to do business with Horizon and:

          -    The company provides goods or services to Horizon, the value of
               which exceeds $1,000 annually; or

          -    They help make Horizon purchasing decisions; or

          -    They have a role in making sure the company gets paid for the
               goods and services it provides.

Approved by Board of Directors - Dec 3, 2003


                                       5
<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                  SECTION 1 (CONTINUED): CONFLICTS OF INTEREST

     -    Obtain advance approval from Horizon's Audit Committee to:

          -    Perform work or services for any person or organization that
               competes with or seeks to do business with Horizon; or

          -    Take a position on the board of directors of another organization
               that competes with, seeks to do business with or has regular
               business dealings with Horizon.

Directors, officers and employees are prohibited from taking for themselves any
opportunity available to Horizon that is discovered through the use of Company
assets, information or position.

BOARDS OF DIRECTORS OF NONPROFIT ORGANIZATIONS

Generally, employees are not prohibited from sitting on the board of directors
of a nonprofit organization but should inform their supervisor prior to
commencing board service. Directors and executive officers should disclose all
other board memberships to Horizon's Nominating and Governance Committee. In all
cases, directors, officers and employees should excuse themselves from any
discussions or votes on any matter involving Horizon to avoid the appearance of
improper behavior.

EMPLOYMENT OF RELATIVES - COMPANY POLICY

Situations may arise where relatives (defined as husband, wife, children,
step-children, mother, father, step-parent, sister, brother, grandparents,
grandchildren, mother-in-law or father-in-law) are employed by Horizon or have a
financial stake in an entity that does business with Horizon. Frequently, this
is not a problem, but the potential for an actual or perceived conflict of
interest may exist. Employees should advise Human Resources of any situations
involving employment of their relatives. Directors and officers should disclose
such information to Horizon's Audit Committee.

Approved by Board of Directors - Dec 3, 2003


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<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                  SECTION 2: FAIR COMPETITION - ANTITRUST LAWS

Horizon succeeds in the marketplace by offering competitively priced, quality
services. The Company strives to support fair competition by complying with
antitrust laws prohibiting activities that reduce competition and restrict
trade.

EXAMPLES OF ANTI-COMPETITIVE BEHAVIOR

The following behavior could be considered anti-competitive and a violation of
antitrust laws:

     -    Any discussions or agreements with a competitor regarding pricing,
          territories, market share or intent to bid (or not bid) for particular
          business or regarding the terms of any contract or agreement with a
          Company customer or supplier;

     -    Providing different information about a request for quotation/proposal
          to competing bidders;

     -    Entering into an exclusive dealing arrangement or understanding where
          you agree to work only with certain suppliers or distributors in a
          particular market where Horizon may have market power;

     -    Taking advantage of market power to eliminate or threaten a competitor
          or potential competitor in that or another market; and

     -    Suggesting that a product or service must be resold at or within a
          particular price or range of prices.

OUR RESPONSIBILITIES

Company personnel must deal fairly with the Company's customers, suppliers and
competitors and are expected to act with integrity by maintaining Horizon's
independence of judgment in the pricing, marketing, purchasing and selling of
all services.

Company personnel are generally expected to:

     -    Understand how fair competition laws apply to the Company's business
          and learn how to avoid engaging in potentially unlawful behavior;

     -    Leave any meeting or informal gathering immediately and contact the
          Legal Department when any type of discussion with competitors begins
          that could be considered anti-competitive;

     -    Refrain from:

               -    Improperly attempting to prevent anyone from competing with
                    Horizon or from entering the markets in which Horizon
                    participates;

               -    Suggesting to suppliers that our purchasing decisions depend
                    on their use of Horizon's goods or services, or that failing
                    to do business with a Horizon subsidiary or affiliate could
                    jeopardize all business with Horizon; and

               -    Making inaccurate or misleading statements about
                    competitors, suppliers, customers or their offerings.

Approved by Board of Directors - Dec 3, 2003


                                       7
<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

            SECTION 3: BRIBERY, KICKBACKS AND OTHER IMPROPER PAYMENTS

Company personnel are expected to maintain the highest level of integrity when
dealing with government officials and members of the private sector.

Anti-bribery laws prohibit companies from directly or indirectly promising,
offering or making payment of money or anything of value to anyone (including a
government official, an agent or employee of a political party, labor
organization or business entity, or a political candidate) with the intent to
induce favorable business treatment or to improperly affect business or
government decisions.

Please note: Anti-bribery laws, anti-kickback laws, and the laws and regulations
that govern the giving of gifts, are complex and can vary from country to
country, and even within a country (e.g., local versus national officials) and
from state to state. This Code does not necessarily take into account all local
legal requirements. Unless otherwise stated in Company policy, more restrictive
local laws take precedence.

OUR RESPONSIBILITIES

Company personnel must avoid giving the impression that they are trying to
influence another person's business decision when giving cash or anything else
of value to third parties. In furtherance of this goal, all Company personnel
are expected to:

     -    Comply with all state, federal and foreign laws and regulations that
          govern gifts, meals and entertainment given to public officials and
          employees of governmental agencies;

     -    Refrain from giving gifts that are intended to influence, or appear to
          influence, business decisions;

     -    Refrain from providing any payment or other kickback in return for
          favorable treatment.

A gift or payment is improper if it is used to influence, or appears to
influence, a business decision. Employees should consult with their supervisor
or manager if they have questions as to whether a gift or payment could be
considered improper. Officers should consult with the Company's General Counsel.

Approved by Board of Directors - Dec 3, 2003


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<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

               SECTION 4: GIFTS, MEALS, SERVICES AND ENTERTAINMENT

The giving and receiving of gifts, meals, services or entertainment can be
important and respectable ways of building and maintaining legitimate business
relationships. However, in order to maintain trust and integrity with the
Company's business partners, it is important to be prudent when accepting gifts.
No director, officer or employee should ever accept a gift that might be
intended to influence, or appears to influence, a business decision.

Decisions about gift giving must be carefully evaluated. In general, Horizon
does not consider ordinary and reasonable business entertainment, or gifts of
nominal value that are customary and legal, to be improper. The Company
recognizes that in certain cultures, gifts of more substantial nature may be
customary and expected. However, the giving of improper gifts or payments can
undermine customer relationships, damage the Company's reputation and subject
the Company to legal penalties.

In addition, certain of the Company's customers and suppliers forbid their
employees from receiving gifts of more than a nominal value in the course of
doing business. Company personnel should comply with the gift and entertainment
policies of the Company's customers and suppliers as if they were a part of this
Code.

OUR RESPONSIBILITIES

Company personnel are expected to act with integrity when deciding whether to
accept a business gift, meal, service or entertainment. Employees who are
buyers, who influence buying, or who are involved in procurement transactions in
any way (e.g., determining specifications, evaluating bids, etc.) must be
mindful of the impression they are making when accepting a business gift, meal
or other form of entertainment.

Generally, Company personnel are expected to:

     -    Accept only personal gifts that would be considered common business
          courtesies and for which they would reasonably expect to give
          something similar in return in the normal course of business;

     -    Ensure business entertainment provided to third parties is reasonable
          and customary;

     -    Offer only gifts that are considered customary, reasonable, legal and
          of nominal value in the local market;

     -    Obtain prior approval of management or another appropriate superior
          before making a decision about whether or not to offer a gift that is
          more than nominal value in the local market;

     -    Comply with the Horizon's policy on "Business Related Expense
          Reporting;" and

     -    Refrain from accepting or requesting any gift, meal, service or
          entertainment that might be intended to influence, or even appears to
          influence, a business decision.

Approved by Board of Directors - Dec 3, 2003


                                       9
<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                 SECTION 5: INTERNATIONAL ETHICS AND COMPLIANCE

Horizon strives to maintain the highest standards of integrity when conducting
business in the United States and abroad. The Company's success in global
business transactions depends on its compliance with country-specific
constraints and conditions and sensitivity to local customs. The laws,
regulations and conventions governing international business relationships vary
from country to country. It is Horizon's policy to comply not only with the
letter of these laws but also with their spirit.

Horizon and its employees are also responsible for following applicable U.S.
laws when doing business outside of the United States. Since violations of those
laws can result in substantial fines, imprisonment and severe restrictions on
the Company's ability to do business, it is essential that Horizon employees
follow them. If local law conflicts with applicable U.S. law, or if in doubt,
ask for guidance before taking any action.

OUR RESPONSIBILITIES

Horizon personnel who conduct business outside of the United States are expected
to be familiar with the laws and regulations of each country in which they
conduct business, as well as the following laws and regulations:

     -    The anti-bribery provisions of the Foreign Corrupt Practices Act
          (FCPA) and the anti-bribery legislation of the Organization for
          Economic Co-operation and Development (OECD) Convention;

     -    U.S. anti-boycott laws;

     -    U.S. Treasury embargo sanctions; and

     -    U.S. exports control restrictions.

All officers and employees are expected to:

     -    Report any FCPA and OECD Convention concerns to their supervisor or
          manager;

     -    Report gifts received from representatives of foreign countries to the
          appropriate supervisor or manager; and

     -    Seek advice in advance from the General Counsel regarding whether a
          payment is legal and legitimate;

     -    Record all payments and transactions accurately and fairly;

     -    Report all requests for boycott support or boycott-related information
          to the General Counsel and the U.S. government;

     -    Obtain technical guidance and advice from the General Counsel about
          export control restrictions when exporting sensitive goods or
          technology;

     -    Seek advice from the General Counsel regarding any sensitive political
          issues with a country in which Horizon is doing or considering doing
          business; and

     -    Receive all training required to understand the laws and regulations
          governing international transactions.

Approved by Board of Directors - Dec 3, 2003


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                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

           SECTION 5 (CONTINUED): INTERNATIONAL ETHICS AND COMPLIANCE

Officers and employees must not:

     -    Make payments or gifts directly or indirectly (such as payments to
          agents, sales representatives or other third parties) if they have
          reason to believe they will be used illegally. This includes corporate
          and personal funds; and

     -    Violate anti-boycott laws, governmental embargoes or export control
          restrictions.

The following are summaries of the key U.S. laws and regulations governing
international business. Because most of these are based on U.S. foreign policy
and national security goals, they are subject to change. It is the individual
responsibility of each officer and employee to stay up to date with any changes
in these laws.

FCPA AND THE OECD CONVENTION LEGISLATION

The FCPA and the legislation implementing the OECD Convention make it a crime to
promise, offer or give anything of value to a government official or political
party or candidate in order to obtain or retain business or gain any improper
advantage. The FCPA covers all countries in which Horizon currently has
operations, and the laws implementing the OECD Convention presently cover many
of those countries.

ANTI-BOYCOTT LAWS

Anti-boycott laws make it against the law to cooperate in any boycotts between
foreign countries not officially sanctioned by U.S. law.

TREASURY EMBARGO SANCTIONS

The Treasury Department's Office of Foreign Assets Control prohibits U.S.
companies and their foreign subsidiaries from doing business with certain
countries, agencies and individuals. Regulations vary depending on the country
and the type of transaction.

EXPORT CONTROL RESTRICTIONS

To prevent sensitive goods, technology and software from falling into the wrong
hands, exports of those products and technical information to certain countries
or individuals is restricted. These restrictions may also apply to transfers
between Horizon and its foreign subsidiaries.

Approved by Board of Directors - Dec 3, 2003


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                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                        SECTION 6: CONTRACT AUTHORIZATION

Horizon's contractual agreements govern its business relationships and ensure
that Horizon's business agreements and confidential information are protected.

Because the laws governing contracts are numerous and complicated, Horizon has
enacted policies and procedures to ensure that contracts entered into by it have
appropriate level of review and approval.

OUR RESPONSIBILITIES

Horizon employees, including officers, who enter into contracts on Horizon's
behalf, must have proper authorization, including legal review where required by
Company policy, prior to the execution of any contract.

All officers and employees must:

     -    Know the types of contracts that they are authorized to execute on
          behalf of the Company, if any;

     -    Comply with Horizon's policies and procedures for entering into
          contracts; and

     -    Where required by Company policy, make sure that the legal department
          reviews and approves any contract.

No officer or employee may enter into any contract on behalf of Horizon without
proper review and authorization.

Approved by Board of Directors - Dec 3, 2003


                                       12
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                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                       SECTION 7: CONFIDENTIAL INFORMATION

CONFIDENTIAL INFORMATION

It is not uncommon for Company personnel to use or review confidential or
proprietary ("confidential information") in the course of doing business. This
includes the Company's confidential information, as well as that of third
parties.

"Confidential or proprietary information" is any information that provides an
entity with some kind of business advantage and is not generally known to the
public. Examples of proprietary information include, but are not limited to:

     -    The Company's bid strategies, bidding activities, pricing information
          and estimates;

     -    Strategic nonpublic information about current and future business
          plans;

     -    Suppliers' pricing and specifications;

     -    Non-public records, such as financial, personnel and personal health
          information records;

     -    Financial earnings results before they are released to the public; and

     -    Information designated as confidential or proprietary.

OUR RESPONSIBILITIES

Company personnel are expected to comply with laws protecting confidential
information from unlawful disclosure. Failure to comply with these laws and
standards can cause irreparable damage Horizon's reputation and result in legal
penalties, adverse regulatory actions and restrictions. It can also prohibit
Horizon from conducting business within certain countries. Directors, officers
and employees, during or subsequent to association or employment with the
Company and without proper authority, may not give or make available to anyone,
or use for his or her own benefit, confidential information derived from
association or employment with the Company.

Company personnel are expected to protect the confidential information of the
Company and third parties by:

     -    Using sensitive information for business purposes only;

     -    Using all applicable Company procedures for labeling and handling
          confidential information;

     -    Sharing confidential information only with appropriate parties both
          within and outside of Horizon;

     -    Making sure that the Company's use of confidential information is
          consistent with its policies, affiliate rules, contractual obligations
          and applicable laws;

     -    Refraining from disclosing confidential information to individuals
          (including other employees, officers and directors) who do not have a
          business need to know the information; and

     -    Preventing access to confidential information under their control
          without proper authorization.

Approved by Board of Directors - Dec 3, 2003


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                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                     SECTION 8: SAFEGUARDING COMPANY ASSETS

COMPANY ASSETS

Horizon invests in and uses certain assets to advance its business strategy and
objectives. Preserving, maintaining, protecting and otherwise taking care of
Company assets is a critical part of the Company's success.

Company assets include, but are not limited to, equipment, tools, machinery,
gear, books, office supplies, fax machines, computers, phones and work time.
Limited personal use of office resources such as office supplies, fax machines,
computers and phones on Company time is generally allowed. However, since
excessive personal use can be costly and impact profitability, all directors,
officers and employees are expected to use good judgment when utilizing these
assets.

The personal use of Horizon equipment, tools and machinery is not allowed,
except where specific business-unit policy allows for such use.

OUR RESPONSIBILITIES

Horizon directors, officers and employees are expected to use Company assets and
resources responsibly and for legitimate business purposes. Employees are
expected to talk to a supervisor when it is unclear if the use of a Company
asset in a given situation is appropriate.

Generally, Company personnel must not:

     -    Take, loan, donate, sell, damage or otherwise use Company assets for
          non-corporate purposes unless specifically authorized;

     -    Reproduce protected materials for personal use;

     -    Make personal use of any Company asset (including computers and other
          office resources, equipment, tools and machinery) that creates any
          additional costs for Horizon, interferes with work duties, or violates
          any Company policies;

     -    Allow Company property to be used for illegal activities; or

     -    Use Company property or information for personal gain.

PURCHASING PRACTICES

All purchasing decisions should be in alignment with Horizon's business
standards and goals and should be result in the best value for Horizon.
Important components of purchasing include competitive bids, partnering
arrangements, incentive-based contracts, quality verification, confirming the
legal and financial condition of the supplier, and avoiding personal conflicts
such as dealing with family members or friends. Purchase agreements should be
written and should adequately set forth the expectations of all parties.

Approved by Board of Directors - Dec 3, 2003


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                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                    SECTION 9: ACCURACY OF BOOKS AND RECORDS/
                                RECORD RETENTION

Horizon expects accountability and accuracy in all accounting and time reporting
practices. All of the Company's books, records, accounts and financial
statements must appropriately reflect the Company's transactions and must
conform to both applicable legal requirements and to the Company's systems of
internal controls. Horizon's system of internal controls helps protect the
Company's financial accountability by:

     -    Assuring management's authorization of financial transactions;

     -    Ensuring that financial transactions are properly recorded and posted;
          and

     -    Satisfying financial and regulatory reporting requirements.

OUR RESPONSIBILITIES

It is critical to the Company's reputation that its financial and non-financial
data be reported accurately. All financial data should be prepared promptly,
carefully, and honestly and treated with discretion. Misstating financial
results could result in serious criminal and civil fines and penalties for
Horizon and personal criminal liability for any director, officer or employee
who falsifies or alters records or reports or who knowingly approves false or
altered records.

The Company is committed to full, fair, accurate and understandable disclosure
in public reports and documents that it filed with, or submits to the Securities
and Exchange Commission (SEC), the Nasdaq Stock Market, Inc., other regulatory
authorities, stockholders and the public. Depending on their position with the
Company, a director, officer or employee may be called upon to provide necessary
information to assure that the Company's corporate reports are complete, fair
and understandable. The Company expects all directors, officers and employees to
take this responsibility seriously and to provide prompt and accurate answers to
inquiries related to the Company's corporate disclosure requirements.

Examples of prohibited behavior in connection with the maintenance of the
Company's books and records include, but are not limited to:

     -    Using questionable accounting techniques in violation of applicable
          legal requirements;

     -    Managing earnings;

     -    Manipulating results to meet targets for incentive plans;

     -    Manipulating financial accounts, records or reports;

     -    Maintaining off-the-book accounts to facilitate questionable or
          illegal payments; or

     -    Taking any action or causing anyone else to take any action to
          influence, coerce, manipulate or mislead auditors for the purpose of
          rendering financial statements misleading.

RECORD RETENTION

Horizon employees create or maintain a variety of corporate records in many
forms, including electronic. Horizon is required by law to keep available for
inspection specific corporate records, usually for a stated minimum period of
time.

Approved by Board of Directors - Dec 3, 2003


                                       15
<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

              SECTION 9 (CONTINUED): ACCURACY OF BOOKS AND RECORDS/
                                RECORD RETENTION

Horizon may be subject to legal sanctions if records are not retained for the
appropriate length of time or are not disposed of properly. Failing to retain
records appropriately could also put the Company at a serious disadvantage in
any litigation.

Legal records could constitute any recorded information, regardless of format or
characteristics. This includes both electronic and non-electronic records.

OUR RESPONSIBILITIES

Directors, officers and employees may not knowingly destroy, alter or falsify
any document, record or object in order to avoid or impede any pending or
potential civil or governmental investigation or proceeding.

Approved by Board of Directors - Dec 3, 2003


                                       16
<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                           SECTION 10: INSIDER TRADING

Horizon's success in the marketplace requires it to maintain the trust and
confidence of the investment community. Horizon's directors, officers and
employees must act with integrity and comply with all applicable laws when
trading public securities, including the Company's securities.

DEFINITION OF INSIDER TRADING

Insider trading may occur when a person:

     -    Knows material non-public information about Horizon or any company
          with whom Horizon has a business relationship; and

     -    Trades that company's securities, such as stocks or bonds, while in
          possession of that information or tell others about it before it is
          made public.

Non-public information, whether positive or negative, is generally "material" if
it might be of significance to an investor in determining whether to purchase,
sell or hold the Company's securities. Information may be significant for this
purpose even if it would not alone determine the investor's decision.

Examples of material non-public information include, but are not limited to:

     -    Plans to issue securities;

     -    Significant changes in earnings patterns;

     -    Major contract awards;

     -    Changes in key management personnel; and

     -    Important regulatory actions affecting the Company, whether positively
          or negatively.

Circumstances suggesting the possibility of insider trading can result in an
investigation by a stock exchange or by governmental authorities. Such an
investigation could damage Horizon's reputation and could result in liabilities
or penalties, including criminal charges and fines against the individual
director, officer or employee.

OUR RESPONSIBILITIES

When trading Horizon securities, including Horizon securities in retirement or
similar accounts, directors, officers and employees are expected to take
precautions to make sure that the trades are not made while in possession of
material non-public information.

Directors, officers and employees are prohibited from:

     -    Trading the securities of Horizon while they are in possession of
          material non-public information;

     -    Trading the securities of Horizon's suppliers or customers or other
          companies with whom Horizon has a business relationship while in
          possession of material non-public information learned in the course of
          employment with the Company;

Approved by Board of Directors - Dec 3, 2003


                                       17
<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                     SECTION 10 (CONTINUED): INSIDER TRADING

     -    Trading the securities of Horizon (or of an applicable outside
          company) until the second business day after any material non-public
          information of which they are aware has been made available to the
          public. This includes any transfers into and out of the Horizon stock
          fund in their savings plans, and changes in patterns involving
          purchases of Horizon securities within the plans (regularly scheduled
          monthly purchases of Horizon securities within plans are not
          prohibited.); and

     -    Giving material non-public information to anyone not authorized to
          have that information, including other Horizon employees and the
          person's friends and family members. If this information is
          subsequently used by the recipient to trade in securities, it is
          considered illegal "tipping" and is a violation of insider trading
          laws. Even a casual remark to a friend or family member may find its
          way to a broker and eventually to the entire financial community,
          thereby requiring the Company to make a premature or unplanned public
          announcement.

     FOR ADDITIONAL INFORMATION, PLEASE REFER TO THE COMPANY'S "INSIDER TRADING
     POLICY".

Approved by Board of Directors - Dec 3, 2003


                                       18
<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                        SECTION 11: PUBLIC COMMUNICATIONS

Horizon employs professionals who are trained and qualified to release
information to the public. Only employees specifically involved in media and/or
public relations or specifically authorized by the CEO should provide
information to the media or to other external parties seeking information on
Horizon's business affairs. The potential risks with respect to inaccurate
statements include claims of false advertising, misrepresentation, breach of
contract, securities fraud or antitrust violations.

The Company is subject to specific rules that govern the reporting of
information to government agencies or elected officials. Only authorized persons
should handle requests for information from these agencies or individuals.

OUR RESPONSIBILITIES

All directors, officers and employees are expected to cooperate fully and
truthfully with regulatory and governmental investigations and proceedings and
to not obstruct other persons from doing so.

Directors, officers and employees are also expected to:

     -    Forward the following types of inquiries to the appropriate
          departments:

<TABLE>
<CAPTION>
          ----------------------------------------------------------------------
          SOURCE                               REFER TO
          ----------------------------------------------------------------------
<S>       <C>                                  <C>
          Financial community                  CFO / Investor Relations
          ----------------------------------------------------------------------
          News or trade media                  CEO / Marketing
          ----------------------------------------------------------------------
          Regulatory agencies                  Legal Department
          ----------------------------------------------------------------------
          Elected officials                    CEO / Legal Department
          ----------------------------------------------------------------------
          Person seeking information about a
          current or former Horizon employee   Human Resources
          ----------------------------------------------------------------------
</TABLE>

     -    Inform their supervisor or other appropriate personnel immediately
          about any request from a government agency or individual that falls
          outside of their routine job responsibilities; and

     -    Report to their supervisors or other appropriate personnel any
          violations of law or this Code that may warrant disclosure to
          appropriate government authorities.

If our personal cooperation has been formally requested (such as by subpoena),
Horizon directors, officers and employees are expected to cooperate fully and
truthfully with regulatory and governmental investigations. Failure to so
cooperate could result in corrective action up to and including termination.

FOR ADDITIONAL INFORMATION, PLEASE REFER TO THE COMPANY'S "FAIR DISCLOSURE
POLICY".

Approved by Board of Directors - Dec 3, 2003

Approved by Board of Directors - Dec 3, 2003


                                       19
<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                    SECTION 12: EQUAL EMPLOYMENT OPPORTUNITY

Horizon seeks to create an atmosphere of inclusion where diversity is valued,
the dignity of each person is respected, and its employees' contributions are
recognized. Directors, officers and employees are expected to demonstrate the
values of teamwork and inclusion by acting with mutual respect and cooperation.
The Company does not tolerate discrimination in the workplace against its
employees.

Directors, officers and employees are expected to comply with laws concerning
discrimination and equal opportunity that specifically prohibit discrimination
on the basis of certain differences. It is Company policy to recruit, select,
train and pay its employees based on merit, experience and other work-related
criteria.

EXAMPLES OF DIFFERENCES PROTECTED BY LAW OR HORIZON POLICY

Differences protected by law or by Horizon policy include:

     -    Race

     -    Gender

     -    Religion

     -    Color

     -    National origin

     -    Age

     -    Disability

     -    Veteran status

     -    Marital status

OUR RESPONSIBILITIES

All personnel are expected to treat others with respect in the course of
performing their job or duties and to comply with equal employment opportunity
laws, including those related to discrimination and harassment.

Generally, Company personnel should not:

     -    Use any differences protected by law as a factor in hiring, firing or
          promotion decisions;

     -    Use any differences protected by law when determining terms or
          conditions of employment, such as work assignments, employee
          development opportunities, vacation or overtime; and

     -    Retaliate against any person who makes a complaint of discrimination
          in good faith, or participates in an investigation.

Approved by Board of Directors - Dec 3, 2003


                                       20
<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                     SECTION 13: HARASSMENT IN THE WORKPLACE

Horizon is committed to maintaining a positive work environment where all
employees are treated with dignity and respect. Harassment of any kind in the
workplace is not tolerated. The Company encourages its directors, officers and
employees to demonstrate inclusion and teamwork by valuing the dignity of every
person, honoring differences and reporting incidents of harassment to the
appropriate persons.

Harassment generally means offensive conduct that is severe and pervasive and
singles out an employee to the detriment or objection of that employee because
of a difference protected by law or Horizon policy. Depending on the situation,
a wide range of conduct could be viewed as harassment, from direct requests of a
sexual nature to situations where offensive behavior (e.g., insults, offensive
jokes or slurs, offensive material posted in the workplace, etc.) results in a
hostile work environment.

OUR RESPONSIBILITIES

All Company personnel are expected to do their part to ensure a safe and secure
workplace in which employees can perform their duties without fear of
harassment.

Any person who believes he or she has been discriminated against or harassed is
encouraged to report such activity to his or her supervisor, or if reporting to
the supervisor would be inappropriate under the circumstances, to another
superior or to the General Counsel. Reports of harassment will be promptly and
thoroughly investigated in as confidential a manner as possible. Horizon will
take appropriate action if harassment is determined to have occurred.

Approved by Board of Directors - Dec 3, 2003


                                       21
<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                   SECTION 14: HEALTH, SAFETY, AND ENVIRONMENT

Protecting and responsibly managing natural resources demonstrates environmental
stewardship and is critical to the quality of life in the communities Horizon
serves and Horizon's long-term business success. The health and safety of
co-workers, customers, subcontractors and communities is the responsibility of
all Horizon directors, officers and employees.

Horizon strives to provide a safe and healthy work place for its employees and
for visitors to its facilities by encouraging:

     -    Compliance with all with environmental, health and safety laws,
          regulations and other requirements; and

     -    The systematic implementation of Horizon's health, safety, and
          environment (HSE) policies and standards.

OUR RESPONSIBILITIES

All Company personnel are expected to:

     -    Comply with all applicable environmental, health and safety laws,
          regulations, permits and other requirements that pertain to

               -    Employee and public safety and health;

               -    Work conditions;

               -    Pollution control; and

               -    Waste management.

     -    Follow work instructions or procedures on environmental, health and
          safety laws, regulations and risk management, and apply training to
          protect others, the environment and themselves;

     -    Promptly report to their supervisor or other appropriate personnel,
          all environmental, health and safety incidents, including significant
          near misses;

     -    Report to work fit to perform their duties free of the effects of
          alcohol or drugs not administered under the care of a physician;

     -    Be sure the Horizon work environment is safe at all times;

     -    Understand and incorporate the Company's HSE responsibilities into
          daily work activities;

     -    Not possess or use weapons while on Horizon premises or vessels or
          while engaged in Horizon business, unless expressly authorized to do
          so;

     -    Not use, possess, sell or transfer illegal drugs, illegal narcotics or
          alcohol while on Horizon premises or vessels or while engaged in
          Horizon business.

FOR ADDITIONAL INFORMATION, PLEASE REFER TO THE COMPANY'S "HS & E POLICIES".

Approved by Board of Directors - Dec 3, 2003


                                       22
<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                SECTION 15: INFORMATION AND INFORMATION RESOURCES

Horizon's information systems support internal and external business activities.
Because these resources connect the Company with the outside world, they are
vulnerable to attack or exploitation by third parties. All Horizon employees,
not just its information technology professionals, are therefore responsible for
information security.

The Company considers all data and communications transmitted or received by or
contained in the Company's electronic or telephonic equipment and systems or
maintained in written form to be Company property. Employees and other users of
the equipment or systems should have no expectation of privacy with respect to
those data and communications.

OUR RESPONSIBILITIES

Horizon expects its information and information systems to be used and managed
appropriately. All personnel are expected to:

     -    Follow all policies and procedures related to the protection of
          information and information resources, including network access and
          appropriate use of the Internet and e-mail;

     -    Report any unusual activities to the Director of Information
          Technology or to Internal Audit as quickly as possible;

     -    Refrain from letting personal use of information system technologies
          interfere with Horizon business activities or incur unnecessary cost;
          and

     -    Refrain from letting business or non-business use of information and
          information resources violate Horizon policies or legal requirements.

Please note that Horizon randomly monitors the usage of Horizon-provided
information technologies, including the Internet and e-mail, for misuse or
abuse, except where prohibited by law.

FOR ADDITIONAL INFORMATION, PLEASE REFER TO THE COMPANY'S "ELECTRONIC
COMMUNICATIONS POLICY."

Approved by Board of Directors - Dec 3, 2003


                                       23
<PAGE>
                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                     SECTION 16: LAWS, RULES AND REGULATIONS

Horizon is subject to numerous local, state, federal and provincial laws, rules
and regulations. Any violation of a law, rule or regulation could damage the
Company's reputation to the detriment of its stockholders and could lead to
severe punitive actions. All directors, officers and employees are expected to
understand, respect and comply with all of the laws, rules, regulations,
policies and procedures that apply to them in their position with the Company.

OUR RESPONSIBILITIES

All directors, officers and employees are expected to comply with all applicable
laws, rules and regulations and to:

     -    Be aware of the laws, rules and regulations that affect their daily
          job responsibilities;

     -    Attend training on those laws, rules and regulations; and

     -    Consult with their supervisor or the Company's General Counsel if they
          have any questions about the existence, applicability or
          interpretation of any law, rule or regulation.

Approved by Board of Directors - Dec 3, 2003


                                       24
<PAGE>
                                                                      APPENDIX A

                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

             HOW TO ASK QUESTIONS OR REPORT VIOLATIONS; ENFORCEMENT

QUESTIONS AND GUIDANCE

If you have any questions about policies, practices or this Code of Ethics and
Business Conduct, talk to your immediate supervisor or manager. If for some
reason you are uncomfortable speaking with your immediate supervisor, please
talk to another member of management or the Company's General Counsel. Don't put
it off. Time may be of the essence in avoiding a bigger problem.

You may also seek advice and counsel from the Company's functional departments
such as Human Resources, Finance, Internal Audit and Legal.

The Company has developed the following procedures to ensure the prompt and
consistent enforcement of the Code, protection for persons reporting
questionable behavior, clear and objective standards for compliance, and a fair
process by which to determine violations.

REPORTING ILLEGAL OR UNETHICAL CONDUCT

REPORTING SUSPECTED OR KNOWN VIOLATIONS COMMITTED BY COMPANY DIRECTORS OR
OFFICERS

Directors, officers or employees who suspect or know of violations of the Code
or otherwise illegal or unethical business or workplace conduct by Company
directors or officers have an obligation to report such violations or conduct to
the Audit Committee of the Company's Board of Directors by writing to the
Chairman of the Audit Committee, at the following address:

Chairman of the Audit Committee of the Board of Directors
ID # XXX-XXX-XXXX (refer to Horizon intranet web site for ID #)
c/o MessagePro
9700 Bissonet Suite 1500
Houston, TX 77036 USA

The Chairman will promptly forward all such reports to the Audit Committee for
its review.

REPORTING SUSPECTED OR KNOWN VIOLATIONS COMMITTED BY COMPANY EMPLOYEES

Employees who suspect or know of violations of this Code or otherwise illegal or
unethical business or workplace conduct by other employees have an obligation to
contact their supervisor or manager, who must promptly inform the Company's
General Counsel of the suspected or known violation.

Officers and directors who suspect or know of violations of this Code or
otherwise illegal or unethical workplace conduct by employees must contact the
Company's General Counsel directly.

Approved by Board of Directors - Dec 3, 2003


                                       25
<PAGE>
                                                                      APPENDIX A

                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

             HOW TO ASK QUESTIONS OR REPORT VIOLATIONS; ENFORCEMENT

If the supervisor or General Counsel is not responsive, or if there is reason to
believe that reporting to such individuals is inappropriate in particular cases,
then the director, officer or employee may contact the Chairman of the Audit
Committee of the Board of Directors.

HORIZON'S ETHICS HOTLINE FOR ACCOUNTING AND AUDIT RELATED ISSUES AND CONCERNS

Horizon's ethics regarding its accounting, internal accounting controls and
financial reporting or audit matters are critical to maintaining the public's
trust and a positive company perception. We have established a procedure to
alert the company and the Audit Committee to potential problems before they have
serious consequences, in compliance with the provisions of the Sarbanes-Oxley
Act of 2002.

Employees should call a toll-free number (refer to Horizon intranet for
toll-free number), if they have specific concerns about a Horizon Offshore
accounting or financial audit matter. The call will be taken by an independent,
third party vendor, who is responsible for maintaining the confidentiality of
the concerns and the anonymity of the caller. The exact contents of the call
will be forwarded directly to the Chairman of the Audit Committee of the Board
of Directors for Horizon.

If you wish to call anonymously, you will be provided a number to use in
identifying your inquiry. The group of professionals who answer your call will
work with you to get the information the Company needs to address your concern.

In the event the employee's call is not anonymous, the Company will treat the
employee's identity and the alleged illegal or unethical conduct as confidential
information, and will disclose the identity of such source only as necessary to
comply with legal requirements and investigate the reported incident. Those
informed of the employee's identity will be made aware of the need for
confidentiality.

Written complaints regarding accounting and audit issues must be sent to:

a) Communication in English

Chairman of the Audit Committee of the Board of Directors
ID # XXX-XXX-XXXX (refer to Horizon intranet web site for ID #)
c/o MessagePro
9700 Bissonnet, Suite 1500
Houston, TX 77036, USA

b) Communication in languages other than English

Chairman of the Audit Committee of the Board of Directors
ID # XXX-XXX-YYYY(refer to Horizon intranet web site for ID #)
c/o MessagePro
9700 Bissonnet, Suite 1500
Houston, TX 77036, USA

Approved by Board of Directors - Dec 3, 2003


                                       26
<PAGE>
                                                                      APPENDIX A

                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

             HOW TO ASK QUESTIONS OR REPORT VIOLATIONS; ENFORCEMENT

ENFORCEMENT

Horizon's General Counsel and Internal Audit will coordinate the resolution of
all complaints. Resolution of complaints may require the involvement of Internal
Audit, Legal, Human Resources and other departmental management as necessary.
The Company will endeavor to treat the identity of all persons reporting known
or suspected violations and the alleged illegal or unethical conduct as
confidential information, and will disclose the identity of such source only as
necessary to comply with legal requirements and investigate the reported
conduct. Those informed of the reporting person's identity shall be made aware
of the need for confidentiality.

Upon receipt of a complaint or report regarding a known or suspected violation
of the Code or otherwise illegal or unethical workplace conduct, the General
Counsel in consultation with the Director of Internal Audit or the Audit
Committee, will evaluate the report as to gravity and credibility. If such
persons determine that further action is warranted, they will instruct the
appropriate Company personnel or outside advisor to:

     -    Initiate an informal inquiry or a formal investigation with respect
          thereto;

     -    Prepare a report of such inquiry or investigation;

     -    Make the results of such inquiry or investigation available to the
          appropriate Company personnel for their consideration and action; and

     -    If there is merit to the report, take appropriate disciplinary action,
          up to and including removal or dismissal, and, if warranted, legal
          proceedings.

The Company will not allow retaliation against any employee who reports in good
faith concerns about compliance with the law, compliance with Horizon's Code of
Ethics and Business Conduct, or other ethical concerns. However, anyone who uses
the ethics and compliance program to spread falsehoods or threaten others, or
with the intent to unjustly damage another person's reputation, will be subject
to disciplinary action.

If you become aware of a potential ethical issue or irregularity, you should not
attempt to handle an investigation on your own. Ask for help from Internal
Audit, Legal, Human Resources or use the procedures described above to report
the matter.

Who you talk to is not as important as you talking to somebody. The Company will
stand behind its Code of Ethics and Business Conduct and those who raise issues
in good faith.

Approved by Board of Directors - Dec 3, 2003


                                       27
<PAGE>
                                                                      APPENDIX A

                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

             HOW TO ASK QUESTIONS OR REPORT VIOLATIONS; ENFORCEMENT

CONTACT INFORMATION

The Company's General Counsel can be contacted as follows:

   Via U.S. Mail: Horizon Offshore, Inc.
                  Attn:  Mr. William B. Gibbens, III
                  Executive Vice President and General Counsel
                  2500 CityWest Blvd., Ste. 2200
                  Houston, Texas 77042

   Via E-Mail:    General Counsel - bgibbens@horizonoffshore.com

   Via Telephone: 713-361-2601

Approved by Board of Directors - Dec 3, 2003


                                       28
<PAGE>
                                                                      APPENDIX B

                                                   [HORIZON OFFSHORE, INC. LOGO]

                             HORIZON OFFSHORE, INC.

                       CODE OF ETHICS AND BUSINESS CONDUCT

                              ACKNOWLEDGEMENT FORM

To: General Counsel
    Horizon Offshore, Inc.

     I acknowledge and confirm to Horizon Offshore, Inc. (the "Company") that I
have received, read, understand and will comply with the Company's Code of
Ethics and Business Conduct. I understand that any violation of the Code or
illegal or unethical conduct is subject to disciplinary action, up to and
including removal or dismissal, and, if warranted, legal proceedings.

     I have had an opportunity to ask questions of my supervisor regarding the
Code and any questions I had have been answered satisfactorily.

------------------------------------
Signature

------------------------------------
Date

------------------------------------
Name (Please Print)

*    Please return this signed and dated form to the General Counsel, Horizon
     Offshore, Inc. 2500 CityWest Blvd., Suite 2200, Houston, Texas 77042.

Approved by Board of Directors - Dec 3, 2003


                                       29