EXHIBIT 15.1





            LETTER REGARDING UNAUDITED INTERIM FINANCIAL INFORMATION

The Board of Directors and Stockholders
Input/Output, Inc.

Registration Statement No's. 33-54394, 33-46386, 33-50620, 33-85304, 333-14231,
333-24125, 333-80297, 333-80299, 333-36264, 333-49382, 333-60950.

         With respect to the subject registration statements, we acknowledge our
awareness of the incorporation by reference therein of our report dated November
14, 2001 related to our review of interim financial information. Pursuant to
Rule 436(c) under the Securities Act of 1933 (the "Act"), such report is not
considered part of a registration statement prepared or certified by an
accountant within the meanings of Sections 7 and 11 of the Act.


                                         /s/ PricewaterhouseCoopers LLP


Houston, Texas
November 14, 2001