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                                                                     EXHIBIT 4.2

                              AMENDED AND RESTATED

                                     BY-LAWS

                                       OF

                          McDERMOTT INTERNATIONAL, INC.
                         (as amended to March 7, 2001 )



                                    ARTICLE I

                            Meetings of Stockholders

         Section 1. The annual and any special meetings of the stockholders
shall be held on the date and at the time and place designated in the notice of
such meetings or in a duly executed waiver of notice thereof.

         Section 2. A special meeting of the stockholders may be held at any
time upon the call of the Chief Executive Officer or by order of the Board of
Directors.

         Section 3. Whether or not a quorum is present at any stockholders'
meeting, the meeting may be adjourned from time to time by the vote of the
holders of a majority of the voting power of the shares of the outstanding
capital stock of the Company present in person or represented by proxy at the
meeting, as they shall determine.

         Section 4. Holders of a majority of the voting power of the shares of
the outstanding capital stock of the Company entitled to vote, present in person
or represented by proxy, shall constitute a quorum for the transaction of all
business at any meeting of the stockholders.


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         Section 5. In all matters arising at stockholders' meetings, a majority
of the voting power of the shares of the outstanding capital stock of the
Company present in person or represented by proxy at the meeting shall be
necessary and sufficient for the transaction of any business, except where some
larger percentage is affirmatively required by law or by the certificate of
incorporation.

         Section 6. At any meeting of stockholders, the chairman of the meeting
may appoint two inspectors who shall subscribe an oath or affirmation to execute
faithfully the duties of inspectors with strict impartiality and according to
the best of their ability, to canvass the votes on any matter and make and sign
a certificate of the result thereof. No candidate for the office of director
shall be appointed as such inspector with respect to the election of directors.
Such inspectors shall be appointed upon the request of the holders of ten
percent (10%) or more of the voting power of the shares of the outstanding
capital stock of the Company present and entitled to vote on such matter.

         Section 7. All elections of directors shall be by ballot. The chairman
of the meeting may cause a vote by ballot to be taken upon any other matter, and
such vote by ballot shall be taken upon the request of the holders of ten
percent (10%) or more of the voting power of the shares of the outstanding
capital stock of the Company present and entitled to vote on such matter.


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         Section 8. The meetings of the stockholders shall be presided over by
the Chief Executive Officer, or if he is absent or unable to preside, by the
Chairman and if neither the Chief Executive Officer nor the Chairman is present
or able to preside, then by a Vice Chairman; if more than one Vice Chairman is
present and able to preside the Vice Chairman who shall have held such office
for the longest period of time shall preside; if neither the Chief Executive
Officer nor the Chairman nor a Vice Chairman is present and able to preside,
then the President shall preside; if none of the above is present and able to
preside, then a person shall be elected at the meeting to preside over same. The
Secretary of the Company, if present, shall act as secretary of such meetings
or, if he is not present, an Assistant Secretary shall so act; if neither the
Secretary nor an Assistant Secretary is present, then a secretary shall be
appointed by the person presiding over the meeting.

         The order of business shall be as follows:

         (a) Calling of meeting to order

         (b) Election of chairman and the appointment of a secretary, if
         necessary

         (c) Presentation of proof of the due calling of the meeting

         (d) Presentation and examination of proxies

         (e) Settlement of the minutes of the previous meeting

         (f) Reports of officers and committees


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         (g) The election of directors, if an annual meeting, or a meeting
         called for that purpose

         (h) Unfinished business

         (i) New business

         (j) Adjournment.

         Section 9. At every meeting of the stockholders, all proxies shall be
received and taken in charge of and all ballots shall be received and canvassed
by the secretary of the meeting who shall decide all questions touching the
qualification of voters, the validity of the proxies, and the acceptance or
rejection of votes, unless inspectors shall have been appointed, in which event
such inspectors shall perform such duties and decide such questions with respect
to the matter for which they have been appointed.

         Section 10. At any meeting of the stockholders, only such business
shall be conducted as shall have been brought before the meeting (a) by or at
the direction of the Board of Directors, or (b) by any stockholder of the
Company of record at the time of giving of the notice provided for in this
Section, who shall be entitled to vote at such meeting and who complies with the
notice procedures set forth in this Section. For business to be properly brought
before a stockholder meeting by a stockholder, the stockholder must have given
timely notice thereof in writing to the Secretary of the Company. To be timely,
a stockholder's notice must be addressed to the attention of the Secretary and


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delivered to or mailed and received at the principal executive offices of the
Company not less than 90 days nor more than 120 days prior to the first
anniversary of the preceding year's annual meeting of stockholders; provided,
however, that if the date of the annual meeting is advanced more than 30 days
prior to or delayed by more than 60 days after such anniversary date, notice by
the stockholder to be timely must be so delivered not earlier than the 120th day
prior to such annual meeting and not later than the close of business on the
later of the 90th day prior to such annual meeting or the 10th day following the
day on which public announcement of the date of such meeting is first made by
the Company. The stockholder's notice shall set forth (i) the name and address
of the stockholder proposing such business and of the beneficial owner, if any,
on whose behalf the proposal or nomination is made; (ii) a representation that
the stockholder is entitled to vote at such meeting and a statement of the
number of shares of the Company which are owned by the stockholder and the
number of shares which are beneficially owned by the beneficial owner, if any;
(iii) a representation that the stockholder intends to appear in person or by
proxy at the meeting to nominate the person or persons or to propose the
business specified in the notice; and (iv) as to each person the stockholder
proposes to nominate for election or re-election as a director, the name and
address of such person and such other information regarding such nominee as
would be required in a


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proxy statement filed pursuant to the rules of the Securities and Exchange
Commission had such nominee been nominated by the Board of Directors, and a
description of any arrangements or understandings between the stockholder and
such nominee and any other persons (including their names), pursuant to which
the nomination is to be made, and the written consent of each such nominee to
being named in the proxy statement as a nominee and to serve as a director if
elected; or, as to each matter the stockholder proposes to bring before the
meeting, a brief description of the business desired to be brought before the
meeting, the reasons for conducting such business at the meeting, and any
material interest of the stockholder in such business. The chairman of the
meeting may refuse to permit any business to be brought before an annual meeting
by a stockholder not in compliance with the provisions of this Section.
Notwithstanding the foregoing provisions of this Section, a stockholder shall
also comply with all applicable requirements of the Securities Exchange Act of
1934, as amended, and the rules and regulations thereunder, and with all other
applicable laws, rules and regulations, with respect to the matters set forth in
this Section.


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                                   ARTICLE II

                                    Directors

         Section 1. The business and affairs of the Company shall be managed by
its Board of Directors in accordance with the provisions of the Articles of
Incorporation. The number of Directors shall be as provided in the Articles of
Incorporation.

         Section 2. Meetings of the Board of Directors may be called by the
Chairman or by the Chief Executive Officer or by a majority of the directors by
giving notice to each director.

         Section 3. Meetings of the Board of Directors shall be presided over by
the Chairman, or if the Chairman so requests or is absent or unable to preside,
by the Chief Executive Officer; if neither the Chairman nor the Chief Executive
Officer is present and able to preside, then by a Vice Chairman; if more than
one Vice Chairman is present and able to preside, the Vice Chairman who shall
have held such office for the longest period of time shall preside; if neither
the Chairman nor the Chief Executive Officer nor a Vice Chairman is present and
able to preside, then the President shall preside; if none of the above is
present and able to preside, then one of the Directors shall be elected at the
meeting to preside over same.

         Section 4. Whether or not a quorum is present at any meeting of the
Board of Directors, a majority of the directors present may adjourn the meeting
from time to time as they may determine. Notice need not be given of any such
adjourned


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meeting if the time and place thereof are announced at the meeting at which the
adjournment is taken. Any business may be transacted at the adjourned meeting
which might have been transacted at the original meeting.

         Section 5. Any committee of the Board of Directors shall have and may
exercise the powers of the Board of Directors in the management of the business
and affairs of the Company to the extent provided in the resolution by which
such committee is designated, except that no such committee shall have authority
to alter or amend the By-Laws, or to fill vacancies in either the Board of
Directors or its own membership. In the absence or disqualification of any
member of such a committee, the member or members thereof present at any meeting
and not disqualified from voting, whether or not he or they constitute a quorum,
may unanimously appoint another member of the Board of Directors to act at the
meeting in the place of any such absent or disqualified member. Each such
committee shall meet at stated times or on notice to all by any of its own
number. It shall fix its own rules of procedure. A majority shall constitute a
quorum and the affirmative vote of a majority of those present at a meeting at
which a quorum is present shall be the act of such committee. Each such
committee shall keep minutes of its proceedings.

         Section 6. Directors shall receive as compensation for their services
an amount in addition to actual expenses incident


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to the attending of meetings to be fixed by resolution of the Board of
Directors. Nothing in this section shall be construed to preclude a Director
from serving the Company in any other capacity and receiving compensation
therefor.

         Section 7. Beginning with the Company's 2001 annual meeting of the
stockholders, no person shall be nominated to stand for election or re-election
to the Company's Board of Directors if such person will have attained the age of
70 prior to the date of election or re-election. Any Director elected or
re-elected at or after the Company's 2001 annual meeting of stockholders who
attains the age 70 during a term to which he or she was elected or re-elected
shall continue to serve as a Director until the first annual meeting of the
stockholders immediately following his or her attainment of the age of 70, at
which time said Director shall be deemed to have resigned and retired from the
Board of Directors.

         Section 8. A Director of this Corporation who is, under Section 411(a)
of the Employee Retirement Income Security Act of 1974 of the United States of
America, under a disability to serve as a fiduciary of an employee benefit plan,
as that term is defined in Section 3(3) of said Act shall not serve as a
fiduciary of any such employee benefit plan with respect to which the Company or
any of its subsidiaries is an employer as defined in Section 3(5) of said Act;
and, during the period of such disability, such Director shall be precluded from
acting in any


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manner with respect to any such plan. Any Director who is disabled from serving
as a fiduciary of an employee benefit plan under Section 411(a) of said Act
shall be requested to consent, in writing, to the applicability of this By-Law
to him.

                                   ARTICLE III

                                    Officers

         Section 1. The officers of this Company shall be elected annually by
the Board of Directors at its first meeting following the annual meeting of
stockholders or from time to time and shall hold office until their successors
are elected and qualify, or until their earlier death, resignation or removal.
Such officers shall consist of a Chairman of the Board of Directors, a Chief
Executive Officer, one or more Vice Chairmen of the Board of Directors, a
President, one or more Vice Presidents, a Secretary, a Treasurer and one or more
Controllers. In these By-Laws, the Chairman of the Board of Directors is
sometimes referred to as "Chairman", and the Vice Chairman or Vice Chairmen of
the Board of Directors are sometimes referred to as "Vice Chairman" or "Vice
Chairmen", respectively. The Board of Directors may in addition elect at such
meeting or from time to time one or more Assistant Secretaries and one or more
Assistant Treasurers and one or more Assistant Controllers. Any number of
offices may be held by the same person.


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         Section 2. The officers shall have such powers and duties as may be
provided in these By-Laws and as may be conferred upon or assigned to them by
the Board of Directors from time to time.

         Section 3. The Chairman shall preside over meetings of the Board of
Directors, as stated elsewhere in these By-Laws.

         Section 4. The Chief Executive Officer shall preside over meetings of
the shareholders, as stated elsewhere in these By-Laws; subject to the direction
of the Board of Directors, he shall have and exercise direct charge of and
general supervision over all business and affairs of the Company and shall
perform all duties incident to the office of the Chief Executive Officer of a
corporation, and such other duties as may be assigned to him by the Board of
Directors.

         Section 5. Each Vice Chairman of the Board of Directors shall have and
exercise such powers and perform such duties as may be conferred upon or
assigned to him by the Board of Directors or by the Chief Executive Officer.

         Section 6. The President shall be the Chief Operating Officer of the
Company and shall have and exercise such powers and perform such duties as may
be conferred upon or assigned to him by the Board of Directors or by the Chief
Executive Officer.

         Section 7. Each Vice President shall have and exercise such powers and
perform such duties as may be conferred upon or assigned to him by the Board of
Directors or by the Chief Executive Officer.


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         Section 8. Each Controller shall have and exercise such powers and
perform such duties as may be conferred upon or assigned to him by the Board of
Directors or by the Chief Executive Officer.

         Section 9. The Secretary shall give proper notice of meetings of
stockholders and directors, shall be custodian of the book in which the minutes
of such meetings are kept, and shall perform such other duties as shall be
assigned to him by the Board of Directors or by the Chief Executive Officer.

         Section 10. The Treasurer shall keep or cause to be kept accounts of
all monies of the company received or disbursed, shall deposit or cause to be
deposited all monies and other valuables in the name of and to the credit of the
Company in such banks and depositories as the Board of Directors shall
designate, and shall perform such other duties as shall be assigned to him by
the Board of Directors or by the Chief Executive Officer. All checks or other
instruments for the payment of money shall be signed in such a manner as the
Board of Directors may from time to time determine.

         Section 11. Any officers of the Company may be removed, with or without
cause, by resolution adopted by the Board of Directors at a meeting called for
that purpose.


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                                   ARTICLE IV

                                      Seals

         The corporate seal of this Company shall be a circular seal with the
name of the Company around the border and the word "SEAL" in the center.

                                    ARTICLE V

         Any of these By-Laws may be amended, altered or repealed and additional
By-Laws may be adopted by the Board of Directors by the affirmative vote of a
majority of the whole Board cast at a meeting duly held, except that the vote of
two-thirds of the outstanding shares of the Company entitled to vote shall be
required to amend, alter or repeal Section 1 or Section 8 of Article II or this
Article V (as it applies to said Section 1 and 8 of Article II) of these
By-Laws.

                                   ARTICLE VI

                                 Indemnification

         Section 1. Each person (and the heirs, executors and administrators of
such person) who is or was a director or officer of the Company shall in
accordance with Section 2 of this Article VI be indemnified by the Company
against any and all liability and reasonable expense that may be paid or
incurred by him in connection with or resulting from any actual or threatened
claim, action, suit or proceeding (whether brought by or in the right of the
Company or otherwise), civil, criminal,


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administrative or investigative, or in connection with an appeal relating
thereto, in which he may become involved, as a party or otherwise, by reason of
his being or having been a director or officer of the Company or, if he shall be
serving or shall have served in such capacity at the request of the Company, a
director, officer, employee or agent of another corporation or any partnership,
joint venture, trust or other entity whether or not he continues to be such at
the time such liability or expense shall have been paid or incurred, provided
such person acted, in good faith, in a manner he reasonably believed to be in or
not opposed to the best interest of the Company and in addition, in criminal
actions or proceedings, had no reasonable cause to believe that his conduct was
unlawful. As used in this ARTICLE VI, the terms, "liability" and "expense" shall
include, but shall not be limited to, counsel fees and disbursements and amounts
of judgments, fines or penalties against, and amounts paid in settlement by,
such director or officer. The termination of any actual or threatened claim,
action, suit or proceeding, civil, criminal, administrative, or investigative,
by judgment, settlement (whether with or without court approval), conviction or
upon a plea of guilty or nolo contendere, or its equivalent, shall not create a
presumption that such director or officer did not meet the standards of conduct
set forth in this Section 1.

         Section 2. Every such director and officer shall be entitled to
indemnification under Section 1 of this ARTICLE VI


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with respect to any claim, action, suit or proceeding of the character described
in such Section 1 in which he may become in any way involved as set forth in
such Section 1, if (i) he has been wholly successful on the merits or otherwise
in respect thereof, or (ii) the Board of Directors acting by a majority vote of
a quorum consisting of directors who are not parties to (or who have been wholly
successful with respect to) such claim, action, suit or proceeding, finds that
such director or officer has met the standards of conduct set forth in such
Section 1 with respect thereto, or (iii) a court determines that he has met such
standards with respect thereto, or (iv) independent legal counsel (who may be
the regular counsel of the Company) deliver to the Company their written advice
that, in their opinion, he has met such standards with respect thereto.

         Section 3. Expenses incurred with respect to any claim, action, suit or
proceeding of the character described in Section 1 of this ARTICLE VI may be
advanced by the Company prior to the final disposition thereof upon receipt of
an undertaking by or on behalf of the recipient to repay such amount unless it
is ultimately determined that he is entitled to indemnification under this
ARTICLE VI.

         Section 4. The rights of indemnification under this ARTICLE VI shall be
in addition to any rights to which any such director or officer or any other
person may otherwise be entitled by contract or as a matter of law.