SECOND AMENDMENT TO AMENDED AND RESTATED LOAN AGREEMENT


     THIS  SECOND AMENDMENT TO AMENDED AND RESTATED LOAN AGREEMENT is dated
and effective  as  of  July  31,  1998 (the "Second Amendment"), among OMNI
ENERGY SERVICES CORP., a Louisiana  corporation  (the "Borrower"), AMERICAN
AVIATION  L.L.C., a Missouri limited liability company  ("Aviation"),  OMNI
MARINE & SUPPLY,  INC.,  a Louisiana corporation ("Marine"), HAMILTON DRILL
TECH  INC.,  an  Alberta, Canada  corporation  ("Hamilton"),  and  HIBERNIA
NATIONAL BANK, a national banking association (the "Bank").

                           W I T N E S S E T H:

     WHEREAS, the  Borrower, Aviation, Marine, and the Bank have heretofore
entered into an Amended and Restated Loan Agreement dated as of January 20,
1998, as amended by  First Amendment thereto dated as of March 31, 1998 (as
so amended, the "Loan  Agreement"),  pursuant to which the Bank established
in  favor  of  the  Borrower  certain  credit   facilities   consisting  of
Acquisition Loans, Revolving Loans, and a Term Loan;

     WHEREAS,  subsequent to the execution of the Loan Agreement,  Hamilton
became a wholly-owned subsidiary of the Borrower;

     WHEREAS, the  Loans  by  the  Bank  to the Borrower are guaranteed, IN
SOLIDO, by Aviation, Marine, and Hamilton as the Guarantors;

     WHEREAS, the parties desire to amend and supplement the Loan Agreement
to allow Revolving Loans by the Bank to the  Borrower  under  the Revolving
Loan  Commitment  to  finance  the  Borrower's  acquisition  of  parts  and
supplies;

     WHEREAS,  the  Borrower,  with  the  consent  of  the  Guarantors, has
requested that the Bank make Revolving Loans to the Borrower,  the proceeds
of  which  shall  be  used by the Borrower to capitalize Omni International
Energy Services, Ltd., a Cayman Islands corporation, and said corporation's
participation in a foreign joint venture; and

     WHEREAS, subject to the terms and conditions of the Loan Agreement, as
amended by this Second Amendment, the Bank is willing to make the Revolving
Loan(s) mentioned in the preceding paragraph.

     NOW, THEREFORE, THE  PARTIES  HERETO,  IN  CONSIDERATION OF THE MUTUAL
COVENANTS HEREINAFTER SET FORTH AND INTENDING TO  BE  LEGALLY BOUND HEREBY,
AGREE AS FOLLOWS:

     1.   DEFINED TERMS.  Capitalized terms used herein  which  are defined
in the Loan Agreement are used herein with such defined meanings.

     2.   DEFINED TERMS REVISION.

          (a)  The definition of the term "Borrowing Base Amount" appearing
in  Section  1.1  on  page  3  of the Loan Agreement is hereby deleted  and
restated as follows:

               "BORROWING BASE AMOUNT"  shall  mean:  (a) for the
               Revolving Loan Commitment, at any time, based upon
               the  most recent timely submitted  borrowing  base
               certificate  submitted  by  or  on  behalf  of the
               Borrower (but not less than on a weekly basis), as
               the  same  may  be adjusted by the Bank on a daily
               basis upon review of the Borrower's sales journals
               and  cash  receipts  and  as  a  result  of  field
               examinations  of  the Collateral (using reasonable
               lending   discretion),    the    lesser   of   (i)
               $10,000,000.00, or (ii) the sum of  (x) the amount
               of  Qualified  Receivables  at such time  and  (y)
               advances, using reasonable lending  discretion and
               up   to   the  sublimit  (in  the  aggregate)   of
               $5,000,000.00,    to    finance   the   Borrower's
               acquisition of Eligible Parts  and Supplies, which
               advances are limited to a loan to  value  ratio of
               50%;  or  (b) for the Acquisition Loan Commitment,
               the lesser  of  (i) $9,000,000.00 or (ii) advances
               for acquisitions  of  entities by the Borrower are
               limited to an earnings  multiple  of  less than or
               equal to 5x projected EBITDA of the entity  to  be
               acquired   (based   upon  the  Borrower's  current
               dayrates or contracts)  and  advances  for capital
               expenditures are limited to a loan to value  ratio
               of  75%  for  geophysical  equipment  and  80% for
               aviation  equipment.  Further, for the Acquisition
               Loan Commitment,  advances to finance the purchase
               of geophysical equipment are subject to a sublimit
               (in the aggregate) of $4,000,000.00.


          (b)  The definition of the  term "Guarantor" appearing in Section
1.1  on page 6 of the Loan Agreement is  hereby  deleted  and  restated  as
follows:

               "GUARANTOR"      shall      mean     individually,
               interchangeably, and collectively,  Omni  Marine &
               Supply,  Inc.,  a  Louisiana corporation, and  its
               successors and assigns,  American Aviation L.L.C.,
               a  Missouri  limited liability  company,  and  its
               successors and  assigns,  and  Hamilton Drill Tech
               Inc., an Alberta corporation, and  its  successors
               and  assigns,  and any wholly-owned Subsidiary  of
               Borrower that the Borrower may hereafter acquire.

          (c)  The definition of  the  term "Guaranty" appearing in Section
1.1  on  page 6 of the Loan Agreement is hereby  deleted  and  restated  as
follows:

               "GUARANTY"  shall mean, collectively, that certain
               Commercial Guaranty  dated  January  20,  1998  by
               Aviation  in  favor  of  the  Bank,  that  certain
               Commercial Guaranty dated January 20, 1998 by Omni
               Marine  in  favor  of  the  Bank, and that certain
               Commercial Guaranty dated May 19, 1998 by Hamilton
               in favor of the Bank.

          (d)  The definition of the term "Security  Agreements"  appearing
in  Section  1.1 on pages 9-10 of the Loan Agreement is hereby deleted  and
restated as follows:

               "SECURITY  AGREEMENTS" shall mean (i) that certain
               Commercial Security Agreement dated July 19, 1996,
               by Omni Geophysical  in  favor  of  the  Bank,  as
               amended  by  First  Amendment  thereto dated as of
               June 13, 1997, by Second Amendment  thereto  dated
               as  of  August 6, 1997, by Third Amendment thereto
               dated  as   of   September  30,  1997,  by  Fourth
               Amendment thereto  dated  as of November 21, 1997,
               and by Fifth Amendment thereto dated as of January
               20,   1998,  affecting  all  of   the   properties
               described  therein,  (ii)  that  certain  Security
               Agreement (Fixtures) by Omni Geophysical dated  as
               of  June 13, 1997 in favor of the Bank, as amended
               by First Amendment thereto dated as of January 20,
               1998,  (iii)  the  Aircraft Security Agreement, as
               amended by First Amendment  thereto  dated  as  of
               December 29, 1997, and by Second Amendment thereto
               dated  as  of  January  20,  1998, (iv) Commercial
               Security  Agreement  dated  August   6,   1997  by
               Aviation in favor of the Bank, as amended by First
               Amendment  thereto  dated  as of January 20, 1998,
               (v) Commercial Security Agreement  by the Borrower
               in favor of the Bank dated as of January 20, 1998,
               (vi) Commercial Security Agreement by  Omni Marine
               dated as of January 20, 1998 in favor of the Bank,
               (vii)  Commercial  Security  Agreement by Hamilton
               dated  as of May 19, 1998 in favor  of  the  Bank,
               (viii) all UCC-1 financing statements, and related
               documents  required by the Bank in connection with
               any  of  the foregoing,  (ix)  all  amendments  or
               modifications to any of the foregoing, and (x) all
               additional  security  agreements hereafter granted
               by any Person as security  for  the  Indebtedness,
               together   with   any   and   all   amendments  or
               modifications to any of the foregoing.

          (e)  The  definition  of  the  term "Subsidiaries"  appearing  in
Section 1.1 on page 10 of the Loan Agreement is hereby deleted and restated
as follows:

               "SUBSIDIARIES" shall mean at any date with respect
               to any Person all the corporations  of  which such
               Person at such date, directly or indirectly,  owns
               50%  or  more  of  the  outstanding  capital stock
               (excluding  directors'  qualifying  shares),   and
               "SUBSIDIARY"  means  any  one of the Subsidiaries;
               PROVIDED,  HOWEVER,  the  terms   Subsidiary   and
               Subsidiaries  shall not include Omni International
               and Omni South America.

          (f)  The following definitions are hereby added to Section 1.1 of
the Loan Agreement:

               "ELIGIBLE PARTS  AND  SUPPLIES"  shall  mean  that
               portion of the Borrower's equipment consisting  of
               Parts  and  Supplies  in  which  Bank  has a first
               priority security interest.

               "HAMILTON" shall mean Hamilton Drill Tech Inc., an
               Alberta  corporation, together with its successors
               and assigns.

               "OMNI INTERNATIONAL" shall mean Omni International
               Energy   Services,    Ltd.,   a   Cayman   Islands
               corporation, and its successors and assigns.

               "OMNI SOUTH AMERICA" shall mean Omni International
               Energy  Services-South  America,  Ltd.,  a  Cayman
               Islands  corporation,  and   its   successors  and
               assigns.

               "PARTS  AND  SUPPLIES"  shall mean all  parts  and
               supplies purchased by Borrower  for  use  with  or
               integration into Borrower's equipment, of whatever
               kind.   For  example,  all  replacement  parts and
               supplies for Borrower's marsh and/or swamp buggies
               shall constitute Parts and Supplies.


     3.   REVISIONS TO AFFIRMATIVE COVENANTS.

          (a)  Section 11.1(f) of the Loan Agreement is hereby  deleted and
restated as follows:

               (f)  within fifteen (15) days following the end of
               each calendar  month,  (i)  an  aging  of each the
               Borrower's  and  the  Guarantor's Receivables  and
               accounts  payable,  together  with  a  certificate
               executed by the chief  financial officer(s) of the
               Borrower and the Guarantor, identifying the amount
               of Qualified Receivables  as  of  the  end of such
               month,   in   such   form   and   containing  such
               representations   and  warranties  regarding   the
               Receivables as the Bank may reasonably require and
               (ii)   a  collateral  schedule   identifying   the
               Borrower's   Eligible   Parts   and  Supplies  and
               itemizing the quantity, cost and extended value of
               such Eligible Parts and Supplies, certified by the
               Borrower's chief financial officer, and containing
               such representations and warranties  as  the  Bank
               may reasonably require.

          (b)   Article  XI  of  the  Loan Agreement is hereby amended  and
supplemented to include the following new covenant as Section 11.19:

               SECTION 11.19.  The Borrower  agrees that it shall
               cause Omni International and Omni South America to
               maintain  at all times their respective  registers
               of  shareholders  at  a  location  in  the  Cayman
               Islands.

     4.   REVOLVING  LOANS FOR ELIGIBLE PARTS AND SUPPLIES.  Subject to the
terms and conditions of  the  Loan  Agreement,  as  amended  by this Second
Amendment,  the Bank agrees to make Revolving Loans to the Borrower  up  to
the applicable Borrowing Base Amount and sublimit then in effect to finance
the Borrower's  acquisition  of Eligible Parts and Supplies.  For each such
requested Revolving Loan by the  Borrower,  the  Borrower shall provide the
Bank with a Request for Advance together with a copy of the invoice for the
Parts and Supplies to be purchased by the Borrower.   The Bank reserves the
right (i) to verify and revise, if necessary, the Borrower's computation of
the applicable Borrowing Base Amount and sublimit then  in  effect and (ii)
to  reject,  using  reasonable  lending  discretion,  any such Request  for
Advance.   The Bank agrees that its reasonable lending discretion  will  be
exercised in  a  manner  similar  to  the Bank's review and verification of
Qualified Receivables.

     5.   REVOLVING  LOANS  FOR INVESTMENT  IN  OMNI  INTERNATIONAL  ENERGY
SERVICES, LTD.  Subject to the  terms and conditions of the Loan Agreement,
as amended by this Second Amendment,  the  Bank  agrees  to  make Revolving
Loans  to  the  Borrower in an amount not to exceed $4,200,000.00  (in  the
aggregate), the proceeds  of  which  shall  be  used  by  the  Borrower  to
capitalize  Omni International and/or Omni International's participation in
a foreign joint  venture;  PROVIDED,  HOWEVER,  it is agreed and understood
that  the  availability of such Revolving Loans shall  be  subject  to  the
Borrowing Base  Amount  as  determined  by Qualified Receivables.  For each
such requested Revolving Loan, the Borrower  shall  provide the Bank with a
Request for Advance.  The Bank reserves the right to  verify and revise, if
necessary, the Borrower's computation of the amount available  for advances
under the applicable Borrowing Base Amount then in effect, subject  to  the
sublimit.   Further,  the  Bank  shall  not  be  obligated to make any such
Revolving Loan for the purposes described in this  paragraph  5  unless and
until  all  applicable  conditions  precedent are satisfied, including  the
conditions specified in the last two sentences of paragraph 9.

     6.   REVISION TO USE OF PROCEEDS.  Section 2.2.7 of the Loan Agreement
is hereby amended and supplemented to  permit  the  use  of  proceeds  from
Revolving Loans pursuant to paragraphs 4 and 5 above.

     7.   REVISION  TO  NEGATIVE  COVENANTS.   Section  12.6  of  the  Loan
Agreement  is  hereby  amended and supplemented to include the following as
subparagraph (g) of Section 12.6:

               (g)  Investment  in Omni International and/or in a
                    foreign joint venture participated in by Omni
                    International,  in  an  amount  not to exceed
                    $4,200,000.00 (in the aggregate).

     8.   REPRESENTATION:    NO   DEFAULT.    Pursuant   to  the   Security
Agreements, the Borrower and the Guarantors agree and acknowledge  that any
Revolving  Loan  by the Bank to the Borrower to finance the acquisition  of
Eligible Parts and  Supplies shall be secured, among other Collateral, by a
first ranking security  interest affecting such Eligible Parts and Supplies
in favor of the Bank.  Further, on and as of the effective date hereof, and
after  giving  effect  to this  Second  Amendment,  the  Borrower  and  the
Guarantors confirm, reaffirm and restate the representations and warranties
set forth in the Loan Agreement  and  the  Collateral  Documents; provided,
that each reference to the Loan Agreement herein shall be deemed to include
the Loan Agreement as amended by this Second Amendment.   The  Borrower and
the  Guarantors  also  represent  and  warrant that no Default or Event  of
Default has occurred and is continuing under the Loan Agreement.

     9.   CONFIRMATION  OF  COLLATERAL  DOCUMENTS.    All   of  the  liens,
privileges,  priorities  and  equities existing and to exist under  and  in
accordance with the terms of the  Collateral  Documents are hereby renewed,
extended and carried forward as security for all of the Loans and all other
debts,  obligations  and  liabilities  of the Borrower  to  the  Bank.   In
addition, the parties acknowledge that the  Loans  are guaranteed IN SOLIDO
by Hamilton pursuant to that certain Commercial Guaranty  dated  as  of May
19, 1998 by Hamilton in favor of the Bank.  Further, in the event the  Bank
makes  a  Revolving  Loan(s)  to the Borrower (pursuant to a Request(s) for
Advance by the Borrower) as set  forth in paragraph 5 above, then the Loans
shall also be secured by a first priority  security  interest affecting not
less  than  65%  of  all  outstanding  stock issued by Omni  International,
granted  by  the  Borrower  to  the  Lender,  all  in  form  and  substance
satisfactory to the Bank and its counsel.  In addition, the Borrower agrees
to  provide the Bank with an opinion of Borrower's  counsel  regarding  the
first  priority  security  interest  affecting  not  less  than  65% of all
outstanding  stock  issued  by  Omni  International,  in form and substance
satisfactory to the Bank and its counsel.

     10.  PAYMENT OF EXPENSES.  The Borrower agrees to pay or reimburse the
Bank for all legal fees and expenses of counsel to the  Bank  in connection
with the transactions contemplated by this Second Amendment.

     11.  WAIVER OF DEFENSES.  In consideration of the Bank's execution  of
this   Second   Amendment,  the  Borrower  and  the  Guarantors  do  hereby
irrevocably waive  any  and  all  claims  and/or defenses to payment on any
indebtedness owed by any of them to the Bank  that may exist as of the date
of execution of this Second Amendment.

     12.  AMENDMENTS.   THE LOAN AGREEMENT AND THIS  SECOND  AMENDMENT  ARE
CREDIT OR LOAN AGREEMENTS AS DESCRIBED IN LA. R.S. 6:<section>1121, ET SEQ.
THERE  ARE NO ORAL AGREEMENTS  BETWEEN  THE  BANK,  THE  BORROWER,  MARINE,
AVIATION,  AND  HAMILTON.   THE  LOAN  AGREEMENT, AS AMENDED BY THIS SECOND
AMENDMENT, SETS FORTH THE ENTIRE AGREEMENT  OF  THE PARTIES WITH RESPECT TO
THE  SUBJECT  MATTER  HEREOF  AND  SUPERSEDES ALL PRIOR  WRITTEN  AND  ORAL
UNDERSTANDINGS BETWEEN THE BORROWER,  AVIATION,  MARINE,  HAMILTON  AND THE
BANK, WITH RESPECT TO THE MATTERS HEREIN SET FORTH.  THE LOAN AGREEMENT, AS
AMENDED BY THIS SECOND AMENDMENT, MAY NOT BE MODIFIED OR AMENDED EXCEPT  BY
A  WRITING SIGNED AND DELIVERED BY THE BORROWER, AVIATION, MARINE, HAMILTON
AND THE BANK.

     13.  GOVERNING  LAW:   COUNTERPARTS.   This  Second Amendment shall be
governed  by  and construed in accordance with the laws  of  the  State  of
Louisiana.  This  Second  Amendment  may  be  executed  in  any  number  of
counterparts,  all  of  which  counterparts,  when  taken  together,  shall
constitute one and the same instrument.

     14.  CONTINUED  EFFECT.  Except as expressly modified herein, the Loan
Agreement shall continue  in  full force and effect.  The Loan Agreement as
amended herein is hereby ratified and confirmed by the parties hereto.


           [THE REMAINDER OF THIS PAGE INTENTIONALLY LEFT BLANK]

     IN  WITNESS  WHEREOF,  the parties  hereto  have  caused  this  Second
Amendment to be executed and  delivered as of the date hereinabove provided
by the authorized officers each hereunto duly authorized.

                              OMNI ENERGY SERVICES CORP.


                              By:  /s/  David A. Jeansonne
                                   ------------------------
                                   Name:  David A. Jeansonne
                                   Title:  Chairman of the Board and 
                                           Chief Executive Officer


                              AMERICAN AVIATION L.L.C.
                              BY: OMNI ENERGY SERVICES CORP.,
                                      AS SOLE MEMBER


                              By:  /s/  David A. Jeansonne
                                   ------------------------
                                   Name:  David A. Jeansonne
                                   Title:  Chairman of the Board and 
                                           Chief Executive Officer


                              OMNI MARINE & SUPPLY, INC.


                              By:  /s/  David A. Jeansonne
                                   ------------------------
                                   Name:  David A. Jeansonne
                                   Title:  Chairman of the Board and 
                                           Chief Executive Officer


                              HAMILTON DRILL TECH INC.


                              By:  /s/  David A. Jeansonne
                                   ------------------------
                                   Name:  David A. Jeansonne
                                   Title:  Chairman of the Board and 
                                           Chief Executive Officer


                              HIBERNIA NATIONAL BANK


                              By:  /s/  Tammy M. Angelety
                                   ------------------------
                                   Name:  Tammy M. Angelety
                                   Title:  Assistant Vice President