FIRST AMENDMENT TO LOAN AGREEMENT

THIS FIRST AMENDMENT TO LOAN AGREEMENT (the “Amendment”) made and entered into
on this the 24th day of March, 2010, by and between MITCHAM INDUSTRIES, INC., as
“Borrower,” and FIRST VICTORIA NATIONAL BANK, as “Lender,” to amend, ratify and
confirm that certain Loan Agreement (the “Loan Agreement”) among the parties
hereto dated the 24th day of September, 2008, governing the terms of a line of
credit as therein described and evidenced by a promissory note of even date
therewith in the original principal sum of $25,000,000.00 (the “Loan”).

In consideration of their mutual warranties, covenants and agreements contained
herein, and in said Loan Agreement and Lender’s renewal and extension of the
existing line of credit to Borrower evidenced by the herein described promissory
note, Borrower and Lender hereby warranty, covenant and agree as follows:

1. Borrower acknowledges, represents, warrants, and agrees that Borrower is
presently indebted to Lender in the amount of the current principal balance of
$18,550,000 owing on the promissory note described in Paragraph II.A. of the
Loan Agreement and any accrued interest thereon, and that Borrower has no
defenses, rights of set off, counterclaims, causes of action or any other bars
to enforcement of the obligations governed by the Loan Agreement or this
amendment thereto.

2. Borrower is the Borrower under the Loan Agreement. All of the warranties of
Borrower relating to Borrower’s corporate existence, good standing and authority
to enter into this transaction as set forth in the Loan Agreement are hereby
renewed, restated and confirmed, both as of the date of the Loan Agreement and
the date of this Amendment thereto.

3. The promissory note described in Paragraph II.A. of the Loan Agreement will
be modified to extend the maturity of the principal of the Loan to April 30,
2011, in accordance with the terms of the Modification Agreement that is
attached hereto and made a part of this Amendment. Borrower will execute and
deliver to Lender the Modification Agreement in the form and on the terms as set
forth on Exhibit A.

4. All advances of principal of the Loan after the date of this Amendment will
be in increments of $500,000.00 or multiples thereof, subject to the other
limitations of the Loan Agreement.

5. In addition to the other obligations of Borrower under the Loan Agreement,
Borrower will pay to Lender a commitment fee in the amount of $15,000.00 as
consideration for the modification of the terms of the Loan set forth in this
Amendment and in the Modification Agreement. This commitment fee will be due and
payable to Lender on the date of this Amendment.

6. The Frost National Bank may issue letters of credit requested by Borrower
pursuant to Section V.B. of the Loan Agreement, subject to the approval of
Lender and The Frost National Bank. Any amounts drawn or available to be drawn
on any letter of credit issued by The Frost National Bank pursuant to the Loan
Agreement will reduce the amount of the principal of the Loan which is available
to be advanced by Borrower. Any amounts drawn under any letter of credit issued
by The Frost National Bank will be immediately reimbursed by Lender to The Frost
National Bank by an advance or advances from the principal of the Loan in the
same manner provided in Section V.B. for draws on any letter of credit issued by
Lender pursuant to the Loan Agreement. Neither Lender nor The Frost National
Bank will have any obligation to issue any letter of credit that is not
acceptable to the issuer as to form, terms, and conditions.

7. Borrower will pay, in addition to the fees prescribed in the Loan Agreement
for issuance of any letter of credit, any fees assessed by any other bank or
other parties to the letter of credit transaction.

8 The Loan shall be governed by and subject to all of the terms, covenants and
conditions of the Loan Agreement, as amended, and by the terms of the promissory
note (as amended by the Modification Agreement), and be secured by the same
liens, assignments and security interests as are provided in said notes and the
Loan Agreement, as amended, and in the security documents referenced therein.

9. Borrower and Lender hereby renew, ratify, and confirm all of the warranties,
covenants and agreements contained in the Loan Agreement except to the extent
modified by the terms of this Amendment thereto. The Loan Agreement, as so
amended, and the documents referenced therein constitute the sole and only
agreement of the parties hereto and supersedes any prior oral understandings or
agreements between the parties respecting the subject matter of this agreement.
This Amendment, together with the Loan Agreement and all prior amendments
thereto, shall apply to and govern the extensions of credit described herein and
all renewals, extensions and rearrangements of such indebtedness of Borrower to
Lender.

EXECUTED on the date first hereinabove mentioned in Victoria, Victoria County,
Texas.

MITCHAM INDUSTRIES, INC.

By /s/ Billy F. Mitcham, Jr.
Billy F. Mitcham, Jr.
Its: President BORROWER

FIRST VICTORIA NATIONAL BANK

By: /s/ Herschel Vansickle
Herschel Vansickle
Its: Sr. Vice President

LENDER

EXHIBIT A

MODIFICATION AGREEMENT

THAT WHEREAS, MITCHAM INDUSTRIES, INC., a Texas corporation, hereinafter
referred to as “Borrower,” executed a promissory note to First Victoria National
Bank, hereinafter referred to as “Lender,” in the original principal sum of
Twenty-Five Million Dollars ($25,000,000.00), dated the 24th day of September,
2008, and bearing interest at the Wall Street Journal prime rate determined
daily, as therein provided and evidencing a revolving line of credit providing
for multiple advances, repayment and re-advances within the limits of such
original principal sum; and

WHEREAS, the said note is governed by the terms of a Loan Agreement of even date
therewith between Borrower and Lender and secured as provided in said Loan
Agreement; such security including but not limited to the liens and security
interests described in a Security Agreement of the same date between Borrower
and Lender covering all of the assets of Borrower as described therein and a
Lease and Rental Assignment of the same date covering equipment leases as
described therein, to which reference is heremade for a more particular
description of the same;

WHEREAS, Lender is the present owner and holder of said note, which has a
principal balance of $18,550,000 as of the date hereof; and

WHEREAS, the Borrower and Lender now wish to enter into the following agreement
to modify the terms of the aforementioned note according to the following terms,
and to confirm, ratify, renew, and carry forward the lien and security interests
securing same:

NOW, THEREFORE, it is hereby agreed by Borrower and Lender that the above
described note shall be modified and extended as hereinafter provided. The
principal amount of said note shall continue to bear interest from the date of
advance until paid at the prime rate published in the Wall Street Journal as
being the base rate on corporate loans established by a selected number of the
largest banks in the United States, as such rate is determined daily by Lender.
No representation is made that such base rate is the lowest or best rate charged
by any bank to its customers. In the event the prime rate published by the Wall
Street Journal should cease to be available for any reason, Lender shall select
an index comparable to such rate to determine the rate of interest on this note.

Notwithstanding any other provision in this note or any other loan document to
the contrary, Lender shall not charge or collect and Lender does not intend to
contract for interest in excess of that permitted by law for loans of this kind
by Lender, and to prevent such occurrence, Lender will, at maturity or an
earlier final payment of this note, determine the total amount of interest that
can be lawfully charged or collected by applying the highest lawful rate of
interest to the full periodic balances of principal for the period each is
outstanding and unpaid and compare such amount with the total interest that has
accrued under the terms of said note, and, if necessary, to prevent usury,
reduce the total amount of interest payable by Borrower to the lesser amount. If
the amount of interest that has been collected exceeds the lawful amount, Lender
shall either make direct refund of such excess to Borrower or credit it against
other sums owed by Borrower to Lender, whichever Lender deems appropriate. If at
any time the rate of interest provided for in this note shall exceed the highest
lawful rate, then any subsequent adjustment in the rate of interest on this note
under the terms hereof will not reduce the rate of interest below the highest
lawful rate until the total amount of interest accrued on this note equals the
amount of interest, which would have accrued if there had been no limitation to
the highest lawful rate. As used herein, the term “highest lawful rate” means
the greatest of the rates of interest from time to time permitted under
applicable law. The interest rate for this Note is computed on a 365/365 simple
interest basis; that is, by applying the ratio of the annual interest rate over
the number of days in a year, multiplied by the outstanding principal balance,
multiplied by the actual number of days the principal balance is outstanding.

In the event of default in the payment of said note as it becomes due or is
declared to be due, this note will bear interest at the highest lawful rate from
the date of such default until paid. All past due interest shall bear interest
at the same rate as the principal.

Borrower and Lender further agree that advances and re-advances following
repayment of principal up to the amount of said note will continue to be made to
Borrower from time to time until the maturity of said note in accordance with
Loan Agreement between the parties.

Borrower and Lender further agree that henceforth all interest accruing on the
amounts of principal advanced will be due in thirteen (13) consecutive monthly
installments in the amount of the accrued and unpaid interest on the date each
such installment is due. The first of such installments of interest after the
effective date of this Agreement shall be due on the 30th day of March, 2010,
and a like installment shall be due on the same day of each succeeding calendar
month thereafter until the 30th day of April, 2011, when the entire principal
balance of said note and any remaining accrued and unpaid interest will be due.

Borrower and Lender further agree that all liens, rights, and remedies
heretofore held by Lender to secure the payment of said note will be extended
and brought forward as security for the payment of said note according to the
above terms.

Contemporaneous with the making of this Agreement, Borrower and Lender have
entered into the Amendment to the Loan Agreement of the same date. The
indebtedness evidenced by said note and other indebtedness described in the Loan
Agreement will continue to be subject to and governed by the Loan Agreement, as
amended, and will continue to be secured as described in the Loan Agreement and
in said note. Nothing in this Agreement shall operate to release, waive or
diminish any of the security, rights, or remedies of Lender under the terms of
the Loan Agreement or any security instrument. In all other respects, this
Amendment and the Amendment to the Loan Agreement constitute the entire
agreement of the parties hereto with respect to the modification of the
promissory note described herein and supersede all prior or contemporaneous oral
or written representations, understandings, or agreements as to the same subject
matter.

As the term “Lender” is used in this agreement, it shall be construed to refer
to Lender or to any current owner of said note, if other than Lender.

Borrower and Lender agree that, except as modified by this agreement, said note
shall continue in full force and effect and the same are hereby expressly
ratified and confirmed by Borrower in all respects. This agreement is made for
the purposes of renewing, extending and continuing the unpaid balance owing on
said note and the liens securing same and is not intended to be in
extinguishment or in lieu of said note and liens.

THIS WRITTEN LOAN AGREEMENT REPRESENTS THE FINAL AGREEMENT BETWEEN THE PARTIES
AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS OR SUBSEQUENT
ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN
THE PARTIES.

EXECUTED this the        day of March, 2010, to be effective on the 24th day of
March, 2010.

MITCHAM INDUSTRIES, INC.

By—

Billy F. Mitcham, Jr.

Its: President

BORROWER

FIRST VICTORIA NATIONAL BANK

By—

Its—

LENDER

         
STATE OF TEXAS
      §
COUNTY OF WALKER
  §  

This instrument was acknowledged before me on      , 2010, by Billy F. Mitcham,
Jr., as President of Mitcham Industries, Inc., on behalf of said corporation.

Notary Public, State of Texas

     
STATE OF TEXAS
  §
COUNTY OF VICTORIA
  §

This instrument was acknowledged before me on      , 2010, by      , as       
of First Victoria National Bank, on behalf of said corporation.

      

Notary Public, State of Texas