Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

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

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(Print or Type Responses)

1. Name and Address of Reporting Person * Hernandez Joseph 2. Issuer Name and Ticker or Trading Symbol Blue Water Acquisition Corp. IV [BWIV] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Chief Executive Officer (Last) (First) (Middle) C/O BLUE WATER ACQUISITION CORP. III, 15 E PUTNAM AVENUE, SUITE 363 3. Date of Earliest Transaction (Month/Day/Year) 03/23/2026 (Street) GREENWICH, CT 06830 4. If Amendment, Date Original Filed (Month/Day/Year) 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 (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 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 Class A ordinary shares 03/23/2026 P 275,000 A (1) 275,000 I See footnote(1)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

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 (Month/Day/Year)

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

Warrants to purchase Class A ordinary shares

$11.5

03/23/2026

P

137,500

(2)

(2)

Class A ordinary shares

137,500

(1)

137,500

I

See footnote(1)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Hernandez Joseph C/O BLUE WATER ACQUISITION CORP. III 15 E PUTNAM AVENUE, SUITE 363 GREENWICH, CT 06830	X	X	Chief Executive Officer

Signatures

/s/ Joseph Hernandez		03/24/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	Reflects the 275,000 private units owned by Blue Water Acquisition IV LLC, the Issuer's sponsor (the "sponsor"). Each private unit consists of one Class A ordinary share and one-half of one warrant, with each whole warrant entitling the holder thereof to purchase one Class A ordinary share for $11.50 per share, subject to adjustment. The private units were purchased at $10.00 per unit for an aggregate purchase price of $2,750,000. Joseph Hernandez is the managing member of the sponsor and has voting and dispositive power over the securities held of record by the sponsor. Mr. Hernandez disclaims any beneficial ownership of the securities held by the sponsor, except to the extent of his pecuniary interest therein.
(2)	The warrants included in the private units will become exercisable at the later of 12 months from the closing of the Issuer's initial public offering and 30 days after the completion of its initial business combination and will expire five years after the completion of the initial business combination or earlier upon redemption or liquidation.

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