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

                                  SCHEDULE 13D

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                               (Amendment No. 2)*

                               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)

                                December 5, 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                857,716 shares of Common Stock, $0.01 par value per
                            share ("Common Stock")
    SHARES           -----------------------------------------------------------
 BENEFICIALLY         8.    Shared Voting Power

   OWNED BY                 6,974,824 shares of Common Stock
     EACH            -----------------------------------------------------------
   REPORTING          9.    Sole Dispositive Power

    PERSON                  857,716 shares of Common Stock
     WITH            -----------------------------------------------------------
                     10.    Shared Dispositive Power

                            6,974,824 shares of Common Stock
--------------------------------------------------------------------------------
11.   Aggregate Amount Beneficially Owned by Each Reporting Person

      7,832,540 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)

      15.3%
--------------------------------------------------------------------------------



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 and an amendment
thereto filed on April 28, 2003. These filings relate to equity securities of
Input/Output, Inc. ("I/O"). Only the amendments to the Schedule resulting from
the transaction reported in Item 5 and from events occurring after April 28,
2003 are reproduced below. For a discussion of prior direct and indirect
acquisitions by the Reporting Person of I/O shares and related matters, please
see his original Schedule 13D filed on February 4, 1999 and Amendment No. 1 to
that Schedule filed on April 28, 2003.

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.

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 five wholly-owned
subsidiaries which design, manufacture and sell industrial products. Laitram,
L.L.C.'s and Mr. Lapeyre's address is, and Laitram's principal offices are
located at, 220 Laitram Lane, Harahan, Louisiana 70123.

During the last five years, Mr. 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 he was or is subject to a judgment, 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. Mr. Lapeyre is a citizen of the United States.

ITEM 3. Source and Amount of Funds or Other Consideration.

The purchase price for the shares of I/O Common Stock purchased by Laitram,
L.L.C. ("Laitram"), as described in Item 5(c), was funded through Laitram's
Revolving Line of Credit with Whitney National Bank, as lender and as agent for
Hibernia National Bank and Bank One, NA. The total aggregate principal amount of
the line of credit is $40,000,000. The line of credit is evidenced by a Loan
Agreement dated April 9, 2003, by and among Laitram, its parent and subsidiary
companies, Mr. Lapeyre and the lenders, and three commercial notes dated the
same date. The loan agreement and the notes are filed as Exhibit 99.4 to this
amended Schedule 13D.

ITEM 4. Purpose of Transaction.

Mr. Lapeyre is the President and chief executive officer of Laitram, L.L.C.,
which owns 6,941,044 shares of Common Stock of I/O. Mr. Lapeyre may be deemed to
beneficially own the I/O Common Stock held by Laitram. On December 5, 2003,
Laitram purchased 2,150,000 of those shares of Common Stock of I/O, which were
sold short by purchasers of I/O's convertible senior notes concurrently with the
offering of the notes.



Cusip No. 457652105                                            Page 5 of 8 Pages

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

The Reporting Person and Laitram, L.L.C. hold 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.

The Reporting Person is a director of I/O. In his capacity with I/O, the
Reporting Person may from time to time consider plans or proposals relating to:
the acquisition or disposition of securities of I/O; extraordinary corporate
transactions involving I/O or any of its subsidiaries; selling or transferring a
material amount of assets of I/O or any of its subsidiaries; changing the
present board of directors or management of I/O; materially changing the present
capitalization or dividend policy of I/O; making other material changes in I/O's
business or corporate structure; changing I/O's charter, bylaws or instruments
corresponding thereto or other actions which may affect control of I/O; causing
the I/O Common Stock no longer to be quoted on the New York Stock Exchange;
causing the I/O Common Stock to become eligible for termination of registration
pursuant to Section 12(g)(4) of the Securities Exchange Act of 1934, as amended
(the "Exchange Act"); or taking any action similar to any of those enumerated
above.

Other than as described in the original Schedule 13D filed by the Reporting
Person or any amendment thereto, the Reporting Person does not have any plans or
proposals that relate to or would result in any of the following actions:

o    the acquisition by any person of additional securities of I/O or the
     disposition of securities of I/O;

o    an extraordinary corporate transaction, such as a merger, reorganization or
     liquidation, involving I/O or any of its subsidiaries;

o    a sale or transfer of a material amount of assets of I/O or any of its
     subsidiaries;

o    any change in the present board of directors or management of I/O,
     including any plans or proposals to change the number or term of directors
     or to fill any vacancies on the board;

o    any material change in the present capitalization or dividend policy of
     I/O;

o    any other material change in I/O's business or corporate structure;

o    changes in I/O's charter, by-laws or instruments corresponding thereto or
     other actions which may impede the acquisition of control of I/O by any
     person;

o    causing a class of securities of I/O to be delisted from a national
     securities exchange or to cease to be authorized to be quoted in an
     interdealer quotation system of a registered national securities
     association;

o    causing a class of securities of I/O to become eligible for termination of
     registration pursuant to Section 12(g)(4) of the Exchange Act; or

o    any action similar to any of those enumerated above.

ITEM 5. Interest in Securities of the Issuer.

(a) Mr. Lapeyre may be deemed to be the beneficial owner of 7,832,540 shares of
I/O Common Stock, including 70,000 shares subject to exercisable options,
representing approximately 15.3% of the shares of Common Stock of I/O believed
to be outstanding.

(b) Of the 7,832,540 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 857,716 shares, and may be deemed
to share the power to vote or direct the vote and to dispose or to direct the
disposition of 6,974,824 shares.

Laitram, L.L.C. is the owner of record of 6,941,044 shares of Common Stock of



Cusip No. 457652105                                            Page 6 of 8 Pages

I/O 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 6,941,044
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 Exchange Act, Mr. Lapeyre disclaims the
beneficial ownership of the 6,941,044 shares of Common Stock of I/O owned of
record by Laitram, L.L.C.

Mr. Lapeyre jointly owns with his wife 10,500 shares of I/O 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 7,832,540 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 the
shares beneficially owned by his wife.

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
December 5, 2003, Laitram, L.L.C. purchased 2,150,000 shares of I/O Common Stock
sold short by purchasers of I/O's convertible senior notes concurrently with the
offering of the notes. The purchase price was $3.48 per share.



Cusip No. 457652105                                            Page 7 of 8 Pages

(d) Laitram, L.L.C. is the owner of record of 6,941,044 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   Agreement and Plan of Merger dated as of September 30, 1998 by
               and among I/O Marine, Inc., I/O, DigiCourse, Inc. and The Laitram
               Corporation. (Incorporated by reference to Exhibit 99.1 to the
               Form 8-K filed by I/O on November 30, 1998, Commission File
               No. 1-13402.)

EXHIBIT 99.2   Registration Rights Agreement dated as of November 16, 1998 by
               and between I/O and The Laitram Corporation. (Incorporated by
               reference to Exhibit 99.2 to the Form 8-K filed on behalf of I/O
               on November 30, 1998, Commission File No. 1-13402.)

EXHIBIT 99.3   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. (Incorporated by reference to Exhibit 99.1 filed
               with Amendment No. 1 to Schedule 13D by Mr. Lapeyre on
               April 28, 2003.)

EXHIBIT 99.4   Loan Agreement dated April 9, 2003, by and among Laitram, L.L.C.,
               Laitram Group, Inc., Intralox, Inc., Laitram Machinery, Inc.,
               Lapeyre Stair, Inc., Laitram Machine Shop, L.L.C., Lapeyre
               Properties, L.L.C., James M. Lapeyre, Jr., Whitney National Bank,
               Hibernia National Bank and Bank One, NA, and commercial notes
               thereunder.


                                    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: January 13, 2004



Cusip No. 457652105                                            Page 8 of 8 Pages

                                  EXHIBIT INDEX

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

99.1        Agreement and Plan of Merger dated as of September 30, 1998 by and
            among I/O Marine, Inc., I/O, DigiCourse, Inc. and The Laitram
            Corporation. (Incorporated by reference to Exhibit 99.1 to the
            Form 8-K filed by I/O on November 30, 1998, Commission File
            No. 1-13402.)

99.2        Registration Rights Agreement dated as of November 16, 1998 by and
            between I/O and The Laitram Corporation. (Incorporated by reference
            to Exhibit 99.2 to the Form 8-K filed on behalf of I/O on
            November 30, 1998, Commission File No. 1-13402.)

99.3        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.
            (Incorporated by reference to Exhibit 99.1 filed with Amendment
            No. 1 to Schedule 13D by Mr. Lapeyre on April 28, 2003.)

99.4        Loan Agreement dated April 9, 2003, by and among Laitram, L.L.C.,
            Laitram Group, Inc., Intralox, Inc., Laitram Machinery, Inc.,
            Lapeyre Stair, Inc., Laitram Machine Shop, L.L.C., Lapeyre
            Properties, L.L.C., James M. Lapeyre, Jr., Whitney National Bank,
            Hibernia National Bank and Bank One, NA, and commercial notes
            thereunder.