UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 1 TO FORM S-1 REGISTRATION STATEMENT As filed with the U.S. Securities and Exchange Commission on February 24, 2026. Registration No. 333-291959 UNDER THE SECURITIES ACT OF 1933 Blue Water Acquisition Corp. IV (Exact name of registrant as specified in its charter) (State or other jurisdiction of incorporation or organization) Cayman Islands 6770 N/A (Primary Standard Industrial Classification Code Number) (I.R.S. Employer ...

As filed with the U.S. Securities and Exchange Commission on December 5, 2025. Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Blue Water Acquisition Corp. IV (Exact name of registrant as specified in its charter) (State or other jurisdiction of incorporation or organization) Cayman Islands 6770 N/A (Primary Standard Industrial Classification Code Number) (I.R.S. Employer Identification Number) 15 ...