Sec Form 3 Filing - Richards Jon L. @ DIAMOND OFFSHORE DRILLING, INC. - 2024-03-14

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 Richards Jon L. 2. Issuer Name and Ticker or Trading Symbol DIAMOND OFFSHORE DRILLING, INC. [ DO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) SVP & Chief Operating Officer (Last) (First) (Middle) 777 N. ELDRIDGE PKWY, SUITE 1100 3. Date of Earliest Transaction (MM/DD/YY) 03/14/2024 (Street) HOUSTON, TX77079 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ 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 42,936 D

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 Restricted Stock Units ( 2 ) ( 1 ) ( 1 ) Common Stock 20,118 D Restricted Stock Units ( 2 ) ( 3 ) ( 3 ) Common Stock 17,158 D Restricted Stock Units ( 2 ) ( 4 ) ( 4 ) Common Stock 60,053 D Restricted Stock Units ( 2 ) ( 5 ) ( 5 ) Common Stock 17,248 D Restricted Stock Units ( 2 ) ( 6 ) ( 6 ) Common Stock 20,080 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Richards Jon L. 777 N. ELDRIDGE PKWY SUITE 1100 HOUSTON, TX77079 SVP & Chief Operating Officer Signatures /s/ Terence W. Waldorf Attorney-in-Fact for Jon L. Richards 03/15/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )These restricted stock units were part of an award of 60,354 restricted stock units on July 1, 2021 that vest in in three equal annual installments on July 1, 2022, July 1, 2023 and July 1, 2024. The first two installments vested on July 1, 2022 and July 1, 2023, respectively, and these remaining restricted stock units vest on July 1, 2024. One share of common stock will be delivered with respect to each vested restricted stock unit within 30 days after the applicable vesting date. ( 2 )Each restricted stock unit represents a contingent right to receive one share of common stock. ( 3 )These restricted stock units were part of an award of 25,737 restricted stock units on May 12, 2022 that vest in three equal annual installments on May 12, 2023, May 12, 2024 and May 12, 2025. The first installment vested on May 12, 2023, and these remaining restricted stock units vest in equal annual installments on May 12, 2024 and May 12, 2025. One share of common stock will be delivered with respect to each vested restricted stock unit within 30 days after the applicable vesting date. ( 4 )The restricted stock units were awarded on May 12, 2022 and vest based on the level of the highest 30 consecutive trading day volume-weighted average price of the common stock of the issuer achieved during the three-year period commencing on the grant date (unless terminated earlier in connection with a "change in control" (as defined in the award agreement)). One share of common stock will be delivered with respect to each vested restricted stock unit within 30 days after the applicable vesting date. ( 5 )These restricted stock units were part of an award of 25,874 restricted stock units on January 18, 2023 that vest in three equal annual installments on January 18, 2024, January 18, 2025 and January 18, 2026. The first installment vested on January 18, 2024, and these remaining restricted stock units vest in equal annual installments on January 18, 2025 and January 18, 2026. One share of common stock will be delivered with respect to each vested restricted stock unit within 30 days after the applicable vesting date. ( 6 )The restricted stock units were awarded on January 15, 2024 and vest in three equal annual installments on January 15, 2025, January 15, 2026 and January 15, 2027. One share of common stock will be delivered with respect to each vested restricted stock unit within 30 days after the applicable vesting date.

Remarks: Exhibit List: Exhibit 24 - Power of Attorney

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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