UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13D

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                               (Amendment No. 1)*

                               Input/Output, Inc.

                                (Name of Issuer)

                     Common Stock, $0.01 par value per share
                         (Title of Class of Securities)

                                    457652105
                                 (CUSIP Number)

                              James M. Lapeyre, Jr.
                                220 Laitram Lane
                            Harahan, Louisiana 70123
                                 (504) 733-6000
            (Name, Address and Telephone Number of Person Authorized
                     to Receive Notices and Communications)

                                 March 26, 2003
             (Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
schedule because of Sections 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check
the following box [X].

NOTE: Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Section 240.13d-7 for other
parties to whom copies are to be sent.

*The remainder of this cover page shall be filled out for a Reporting Person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).



CUSIP NO. 457652105                                            Page 2 of 8 Pages

--------------------------------------------------------------------------------
 1.   Name of Reporting Person
      I.R.S. Identification No. of Above Person (entities only)

      James M. Lapeyre, Jr.
--------------------------------------------------------------------------------
 2.   Check the Appropriate Box if a Member of a Group (See Instructions)

      (a) [_]
      (b) [X]
--------------------------------------------------------------------------------
 3.   SEC Use Only

--------------------------------------------------------------------------------
 4.   Source of Funds (See Instructions)

      Not applicable
--------------------------------------------------------------------------------
 5.   Check if Disclosure of Legal Proceedings Is Required Pursuant to Items
      2(d) or 2(e)

--------------------------------------------------------------------------------
 6.   Citizenship or Place of Organization

      United States
--------------------------------------------------------------------------------
                      7.    Sole Voting Power

   NUMBER OF                477,924 shares of Common Stock, $0.01 par value per
                            share ("Common Stock")
    SHARES           -----------------------------------------------------------
 BENEFICIALLY         8.    Shared Voting Power

   OWNED BY                 4,824,824 shares of Common Stock
     EACH            -----------------------------------------------------------
   REPORTING          9.    Sole Dispositive Power

    PERSON                  477,924 shares of Common Stock
     WITH            -----------------------------------------------------------
                     10.    Shared Dispositive Power

                            4,824,824 shares of Common Stock
--------------------------------------------------------------------------------
11.   Aggregate Amount Beneficially Owned by Each Reporting Person

      5,302,748 shares of Common Stock
--------------------------------------------------------------------------------
12.   Check if the Aggregate Amount in Row (11) Excludes Certain Shares
      (See Instructions)

                                                                             [X]
--------------------------------------------------------------------------------
13.   Percent of Class Represented by Amount in Row (11)

      10.3%
--------------------------------------------------------------------------------



Cusip No. 457652105                                           Page 3 of 8 Pages

14.   Type of Reporting Person (See Instructions)

      IN
--------------------------------------------------------------------------------



Cusip No. 457652105                                            Page 4 of 8 Pages

                                  SCHEDULE 13D

Preliminary Statement

This filing by James M. Lapeyre, Jr. (sometimes called the "Reporting Person")
amends a Schedule 13D filed by Mr. Lapeyre on February 4, 1999. Only the
amendments to the Schedule are reproduced below. This statement relates to
equity securities of Input/Output, Inc. ("I/O").

The Reporting Person is a director of I/O and Chairman of its Board of
Directors. As a director of I/O, the Reporting Person may take an active role in
corporate strategy and business decisions involving I/O, and the Reporting
Person has elected to file this Statement on Schedule 13D rather than on
Schedule 13G as a precautionary measure. The election to file this amended
statement on Schedule 13D shall not be deemed an acknowledgment or admission by
the Reporting Person that such a statement is required to be filed pursuant to
Section 240.13d-1(e), or otherwise, or that the Reporting Person holds
securities of I/O with a purpose or effect of changing or influencing the
control of I/O, or in connection with or as a participant in any transaction
having that purpose or effect. Neither does the election to file this amended
statement on Schedule 13D constitute an acknowledgment or admission by the
Reporting Person that the Reporting Person does not continue to be eligible to
file a statement on Schedule 13G, pursuant to Section 240.13d-1(c), as a person
who, among other things, has not acquired such securities with any purpose of,
or with the effect of, changing or influencing the control of I/O, or in
connection with or as a participant in any transaction having that purpose or
effect.

ITEM 1. Security and Issuer

The class of equity securities to which this statement relates is the common
stock, $0.01 par value per share (the "Common Stock"), of I/O, a Delaware
corporation, whose principal executive offices are located at 12300 Parc Crest
Drive, Stafford, Texas 77477.

ITEM 2. Identity and Background.

(c) The Reporting Person, James M. Lapeyre, Jr., is currently employed as the
President and chief executive officer of Laitram, L.L.C., whose principal
business is acting as the parent holding company of four wholly-owned
subsidiaries which design, manufacture and sell industrial products. Laitram,
L.L.C.'s address is, and its principal offices are located at, 220 Laitram Lane,
Harahan, Louisiana 70123.

ITEM 4. Purpose of Transaction.

Mr. Lapeyre is the President and chief executive officer of Laitram, L.L.C., a
successor of The Laitram Corporation. Through a series of transactions that
occurred on September 30, 2002 and December 31, 2002, The Laitram Corporation
was reorganized as an S Corporation for tax purposes, Laitram Group, Inc. was
formed to be the holding company for The Laitram Corporation, and The Laitram
Corporation was reorganized as a limited liability company called Laitram,
L.L.C. Laitram Group, Inc. is the sole member of Laitram, L.L.C., and all but
one of the former shareholders of The Laitram Corporation are now instead the
shareholders of Laitram



Cusip No. 457652105                                            Page 5 of 8 Pages

Group, Inc. The proportionate ownership of each shareholder of The Laitram
Corporation prior to these transactions generally was the same as the
proportionate ownership of each shareholder of Laitram Group, Inc., following
the transactions, except for the effect of the one shareholder who is entitled
to receive cash for her shares of The Laitram Corporation rather than shares of
Laitram Group, Inc., and except that the proportionate ownership of several
shareholders increased slightly because they contributed additional capital to
Laitram Group, Inc. Mr. Lapeyre is also President and chief executive officer of
Laitram Group, Inc.

Prior to the transaction reported in this amendment, Laitram, L.L.C. owned
5,794,000 shares of I/O Common Stock. On March 26, 2003, Laitram, L.L.C.
distributed 1,002,956 shares of Common Stock of I/O as a dividend to its sole
member, Laitram Group, Inc., which immediately thereafter distributed the
1,002,956 shares as a dividend to its shareholders, prorata, including Mr.
Lapeyre, his spouse and his minor child. Certain of the shareholders of Laitram
Group, Inc. who received shares of I/O, including Mr. Lapeyre, have agreed that
for a period of three years, they will not sell the I/O shares they received in
the distribution without the written consent of the majority of the parties to
the agreement, voting in proportion to their ownership of the distributed
shares.

The additional shares of I/O Common Stock reported herein as beneficially owned
by Mr. Lapeyre were acquired through open market transactions or directly from
I/O in lieu of directors' fees. As set forth in Item 5 of this Schedule 13D, Mr.
Lapeyre disclaims the beneficial ownership of certain of those shares.

The Reporting Person holds Common Stock of I/O as an investment. Subject to
market conditions and other factors deemed relevant to him, the Reporting Person
may purchase, directly or indirectly, additional shares of I/O Common Stock or
dispose of some or all of such shares in open market purchases or privately
negotiated transactions.

ITEM 5. Interest in Securities of the Issuer.

(a) Mr. Lapeyre may be deemed to be the beneficial owner of 5,302,748 shares of
Common Stock, representing approximately 10.3% of the shares of Common Stock of
I/O believed to be outstanding.

(b) Of the 5,302,748 shares of Common Stock reported herein as beneficially
owned by Mr. Lapeyre, he has the sole power to vote or to direct the vote and to
dispose or to direct the disposition of 477,924 shares, including 60,000 shares
subject to options that will be exercisable on May 25, 2003, and may be deemed
to share the power to vote or direct the vote and to dispose or to direct the
disposition of 4,824,824 shares.

Laitram, L.L.C. is the owner of record of 4,791,044 shares of Common Stock
reported herein as beneficially owned by Mr. Lapeyre. Mr. Lapeyre has the sole
power as President and chief executive officer of Laitram, L.L.C. to vote or
direct the vote and to dispose or direct the disposition of these 4,791,044
shares, unless the Board of Managers of Laitram, L.L.C. changes that power, in
which case Mr. Lapeyre may be deemed to share such power with the Board.
Pursuant to Rule 13d-4 under the Securities Exchange Act of 1934 (the "Exchange
Act"), Mr. Lapeyre disclaims the beneficial ownership of the 4,791,044 shares of
Common Stock owned of



Cusip No. 457652105                                            Page 6 of 8 Pages

record by Laitram, L.L.C.

Mr. Lapeyre jointly owns with his wife 10,500 shares of Common Stock reported
herein as beneficially owned by him, and she shares with him the power to vote
or to direct the vote and the power to dispose or to direct the disposition of
such securities. In addition to the 5,302,748 shares reported as beneficially
owned by Mr. Lapeyre, Mrs. Lapeyre beneficially owns 30,000 shares of I/O Common
Stock, and she exercises the sole power to vote or direct the vote and to
dispose or direct the disposition of such securities. Pursuant to Rule 13d-4
under the Exchange Act, Mr. Lapeyre disclaims beneficial ownership of these
30,000 shares.

Mr. and Mrs. Lapeyre jointly own as trustees of three separate trusts (each of
which holds 3,500 shares of Common Stock) for the benefit of their three
children 10,500 shares of Common Stock reported herein as beneficially owned by
Mr. Lapeyre. Mr. and Mrs. Lapeyre share the power to vote or to direct the vote
and the power to dispose or to direct the disposition of all such securities.
Pursuant to Rule 13d-4 under the Exchange Act, Mr. and Mrs. Lapeyre disclaim the
beneficial ownership of the 10,500 shares of Common Stock that they jointly own
as trustees.

One of Mr. and Mrs. Lapeyre's three children who is a minor owns 12,780 shares
of I/O Common Stock reported herein as beneficially owned by Mr. Lapeyre. Mr.
and Mrs. Lapeyre share the power to vote or direct the vote and to dispose or
direct the disposition of these shares. Mr. Lapeyre also holds 10,000 additional
I/O shares as custodian for this minor child, over which Mr. Lapeyre has the
sole power to vote or direct the vote and to dispose or direct the disposition.
Pursuant to Rule 13d-4 under the Exchange Act, Mr. and Mrs. Lapeyre disclaim the
beneficial ownership of the 22,780 shares owned by their minor child but
reported herein as beneficially owned by Mr. Lapeyre.

Mr. Lapeyre's wife's name is Sally Huger Lapeyre. Her address is c/o Mr. James
M. Lapeyre, Jr., 220 Laitram Lane, Harahan, Louisiana 70123, and she is not
employed. During the last five years, Mrs. Lapeyre has not been (a) convicted in
a criminal proceeding (excluding traffic violations and similar misdemeanors) or
(b) a party to a civil proceeding of a judicial or administrative body of
competent jurisdiction as a result of which she was or is subject to a judgment,
order, decree or final order enjoining future violations of, or prohibiting or
mandating activities subject to, federal or state securities laws or finding any
violation with respect to such laws. Mrs. Lapeyre is a citizen of the United
States.

(c) During the past sixty days, Mr. Lapeyre has not effected any transactions
involving the Common Stock of I/O except as reported in this Item 5(c). On March
26, 2003, Mr. Lapeyre received shares of I/O Common Stock in the distribution by
Laitram, L.L.C. and re-distribution by Laitram Group, Inc. reported herein in
the following amounts: 240,258 shares (by Mr. Lapeyre); 30,000 shares (by Mr.
Lapeyre's wife); and 12,780 shares (by Mr. Lapeyre's minor child). Mr. Lapeyre
also purchased shares of I/O Common Stock in open market transactions through a
broker-dealer on the following dates and in the following amounts: February 6,
2003: 10,000 shares at $3.94 per share, 3,800 shares at $3.92 per share, 1,200
shares at $3.89 per share, and 5,000 shares at $3.88 per share; February 7,
2003: 4,000 shares at $4.00 per share; and February 10, 2003: 4,900 shares at
$3.79 per share, 100 shares at $3.78 per share, 5,000 shares at $3.84 per share,
and 6,000 shares at $3.82 per share.



Cusip No. 457652105                                            Page 7 of 8 Pages

(d) Laitram, L.L.C. is the owner of record of 4,791,044 shares of Common Stock
reported herein as beneficially owned by Mr. Lapeyre. As such, Laitram, L.L.C.
has the right to receive or the power to direct the receipt of dividends from,
or the proceeds from the sale of, such securities, and such right or power
relates to more than 5% of the issued and outstanding shares of the Common Stock
of I/O.

Certain shares of I/O Common Stock owned by Mr. Lapeyre may be deemed community
property under Louisiana law, and in that case both he and his wife would be
deemed to have the right to receive or the power to direct the receipt of
dividends from, or the proceeds from the sale of, such shares. In addition, both
Mr. and Mrs. Lapeyre are deemed to have the right to receive or the power to
direct the receipt of dividends from, or the proceeds from the sale of, shares
of I/O Common Stock owned of record by their minor child.

ITEM 6. Contracts, Arrangements, Understandings or Relationships With Respect to
Securities of the Issuer.

In connection with the distribution by Laitram, L.L.C. on March 26, 2003, of
1,002,956 shares of I/O Common Stock to Laitram Group, Inc., its sole member,
and the re-distribution of such shares prorata by Laitram Group, Inc. to its
shareholders, certain of the Laitram Group, Inc. shareholders agreed that for a
period of three years, they will not sell the I/O shares they received in the
distribution without the written consent of the majority of the parties to the
agreement, voting in proportion to their ownership of the distributed shares.
The shareholders of Laitram Group, Inc. who are parties to that agreement are
James M. Lapeyre, Jr., G. Charles Lapeyre, Philip F. Lapeyre, Monique Lapeyre
McCleskey, Robert S. Lapeyre, Andrew B. Lapeyre and Amy Lapeyre Gui.

Description of the contents of any document referred to in this Schedule 13D and
filed or incorporated by referenced as an exhibit hereto is necessarily not
complete and, in each instance, reference is made to the document itself which
is filed as an exhibit herewith or incorporated as an exhibit herein by
reference.

ITEM 7. Material to be Filed as Exhibits.

EXHIBIT 99.1   Shareholders Agreement dated March 26, 2003, among James M.
               Lapeyre, Jr., G. Charles Lapeyre, Philip F. Lapeyre, Monique
               Lapeyre McCleskey, Robert S. Lapeyre, Andrew B. Lapeyre and Amy
               Lapeyre Gui.

                                    SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

                           /s/ James M. Lapeyre, Jr.
                          ----------------------------
                          James M. Lapeyre, Jr.

Dated: April 28, 2003



Cusip No. 457652105                                            Page 8 of 8 Pages

                                  EXHIBIT INDEX

Exhibit
Number      Description
------      -----------

99.1        Shareholders Agreement dated March 26, 2003, among James M. Lapeyre,
            Jr., G. Charles Lapeyre, Philip F. Lapeyre, Monique Lapeyre
            McCleskey, Robert S. Lapeyre, Andrew B. Lapeyre and Amy Lapeyre Gui.