Rubico Inc美股招股说明书(2026-08-17版)

Up to 50,000,000 Common Shares RUBICO INC. This is a supplement (the “Prospectus Supplement”) to the prospectus, dated May 1, 2026 (as supplemented or amended from time to time, the “Prospectus”)of Rubico Inc. (the “Company”), which forms a part of the Company’s Registration Statement on Form F-1 (Registration Nos. 333-295199 and 333-297277), asamended from time to time. This Prospectus Supplement is being filed to update and supplement the information included in the Prospectus with the information contained in theCompany’s Reports on Form 6-K, furnished to the U.S. Securities and Exchange Commission (the “Commission”) on July 31, 2026, August 7, 2026, August 14, 2026and August 17, 2026 (the “Forms 6-K”). Accordingly, the Forms 6-K are attached to this Prospectus Supplement. This Prospectus Supplement should be read in conjunction with, and delivered with, the Prospectus and is qualified by reference to the Prospectus except to theextent that the information in this Prospectus Supplement supersedes the information contained in the Prospectus. This Prospectus Supplement is not complete without, and may not be delivered or utilized except in connection with, the Prospectus, including anyamendments or supplements to it. Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page 10 of the Prospectus for a discussion of informationthat should be considered in connection with an investment in our securities. Neither the Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus istruthful or complete. Any representation to the contrary is a criminal offense. The date of this prospectus supplement is August 17, 2026. UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549FORM 6-KREPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934For the month of July 2026Commission File Number:001-42684Rubico Inc.(Translation of registrant's name into English)20 Iouliou Kaisara Str19002, PaianiaAthens - Greece(Address of principal executive office)Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.Form 20-F [X ]Form 40-F [] INFORMATION CONTAINED IN THIS FORM 6-K REPORT On July 28, 2026, the Registrant issued a press release relating to the acquisition of Chemical/Product Oil Tankers, a copy of which is attached hereto asExhibit 99.1. The Share Purchase Agreement On July 27, 2026, Rubico Inc. (the “Company”) entered into a Share Purchase Agreement (the “SPA”) with Top Ship Inc. (the “Seller”), an affiliate of Mr. EvangelosPistiolis, to purchase 500 registered shares of Roman Shark V Inc. (the “SPV”), representing all of the issued and outstanding shares of the SPV. The SPV has enteredinto a shipbuilding contract with Guangzhou Shipyard International Company Limited and China Shipbuilding Trading Co., Ltd. for the purchase of a 47,499 dwtchemical/product oil carrier. The tanker is scheduled for delivery in the second quarter of 2029. The purchase price for all of the shares of the SPV is approximately $6.5 million (the “Purchase Price”) which is payable on the closing of the acquisition of the SPV(the “Closing”) no later than September 30, 2026. A previously paid advance cash payment of $0.3 million will be credited against the Purchase Price. The Companymay elect to make the payment of any unpaid part of the Purchase Price for the SPV in the form of newly-issued Series G Preferred Shares. Pursuant to the SPA, to the extent the Company raises capital through the issuance of any common stock, preferred stock, or other equity interest prior to the Closing,the Company shall be obligated to apply 100% of the net cash proceeds of such financing or equity raises directly toward the payment of the Purchase Price at Closing(the “Cash Sweep”). The Seller may waive the Cash Sweep unilaterally by notifying the Company prior to the Closing. The Seller has also secured time charter employment with a major oil trader for the vessel, starting from its delivery and for a firm duration of seven years, withcharterer’s option to extend for four additional years. The total potential gross revenue backlog from this contract, including optional years, is about $75.4 million. The SPV has entered into a definitive sale and leaseback financing agreement (“Financing”) with ABC Financial Leasing Co., Ltd., a major Chinese leasing company,or its controlled subsidiaries. The Financing is in an aggregate amount of 85% of the pre-delivery installments payable under the shipbuilding contract. The aggregateamount of pre-delivery installments payable under the shipbuilding contract is $45.2 million, out of which $6.8 million has already been settled. The Financing bears aneffective interest rate of Term SOFR plus a margin of 1.80%. Under the Financing, upon delivery of the vessel the Company will make quarte