Sec Form 3 Filing - Gates Capital Management, Inc. @ ION GEOPHYSICAL CORP - 2021-04-20

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Gates Capital Management, Inc. 2. Issuer Name and Ticker or Trading Symbol ION GEOPHYSICAL CORP [ IO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 1177 AVE. OF THE AMERICAS, 46TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 04/20/2021 (Street) NEW YORK, NY10036 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock, par value $0.01 per share ("Common Stock") 4,713,354 I See footnote ( 1 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares 8.0% Second Lien Convertible Notes, due 2025 ( 4 ) ( 2 ) ( 2 ) Common Stock ( 3 ) ( 3 ) ( 4 ) I ( 1 ) See footnote ( 1 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Gates Capital Management, Inc. 1177 AVE. OF THE AMERICAS 46TH FLOOR NEW YORK, NY10036 X Gates Jeffrey L 1177 AVENUE OF THE AMERICAS 46TH FLOOR NEW YORK, NY10036 X Gates Capital Management, L.P. 1177 AVENUE OF THE AMERICAS 46TH FLOOR NEW YORK, NY10036 X Gates Capital Management GP, LLC 1177 AVENUE OF THE AMERICAS 46TH FLOOR NEW YORK, NY10036 X Signatures Gates Capital Management, L.P., By: Gates Capital Management GP, LLC, its general partner, By: Gates Capital Management, Inc., its managing member, By: /s/ Jeffrey L. Gates, President 04/30/2021 Signature of Reporting Person Date Gates Capital Management GP, LLC, By: Gates Capital Management, Inc., its managing member, By: /s/ Jeffrey L. Gates, President 04/30/2021 Signature of Reporting Person Date Gates Capital Management, Inc., By: /s/ Jeffrey L. Gates, President 04/30/2021 Signature of Reporting Person Date Jeffrey L. Gates, By: /s/ Jeffrey L. Gates 04/30/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Gates Capital Management, L.P. ("Gates Capital"), acts as the investment manager to certain funds (the "Gates Capital Funds") directly holding the securities reported herein. Gates Capital Management GP, LLC (the "General Partner") is the general partner of Gates Capital. Gates Capital Management, Inc. (the "Corporation"), is the managing member of the General Partner. Jeffrey L. Gates serves as President of the Corporation Each of Gates Capital, the General Partner, the Corporation and Jeffrey L. Gates, may be deemed to share beneficial ownership of the securities reported herein. Each of Gates Capital, the General Partner, the Corporation and Jeffrey L. Gates, disclaims beneficial ownership of the securities reported herein except to the extent of its or his pecuniary interests therein, if any. ( 2 )The Issuer's 8.0% New Second Lien Convertible Notes (the "New Second Lien Convertible Notes") are convertible at the election of the holder at any time prior to the close of business on the trading day immediately preceding December 15, 2025, the maturity date of the New Second Lien Convertible Notes. ( 3 )Upon conversion of the New Second Lien Convertible Notes, the settlement of the conversion right may, at the option of the Issuer, be in the form of shares of Common Stock, cash or a combination of cash and shares of Common Stock. ( 4 )The Gates Capital Funds hold an aggregate of $70,479,000 in principal amount of the New Second Lien Convertible Notes are convertible into shares of Common Stock at an initial conversion rate of 333.3333 shares of Common Stock per $1,000 principal amount of New Second Lien Convertible Notes (subject to adjustment in certain circumstances in accordance with the terms of the New Second Lien Convertible Notes).

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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