Rubico Inc美股招股说明书(2025-09-30版)

75,000 Common SharesOffered by the Selling Shareholders RUBICO INC. This is a supplement (“Prospectus Supplement”) to the prospectus, dated September 19, 2025 (“Prospectus”) of Rubico Inc. (the“Company”), which forms a part of the Company’s Registration Statement on Form F-1 (Registration No. 333-289552). On September 30, 2025, the Company filed a Current Report on Form 6-K with the U.S. Securities and Exchange Commission(the “Commission”) as set forth below. This Prospectus Supplement should be read in conjunction with, and delivered with, the Prospectus and is qualified by reference tothe Prospectus except to the extent that the information in this Prospectus Supplement supersedes the information contained in theProspectus. This Prospectus Supplement is not complete without, and may not be delivered or utilized except in connection with, theProspectus, including any amendments or supplements to it. Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page 8 of the Prospectus for adiscussion of information that should be considered in connection with an investment in our securities. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of thesesecurities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense. The date of this prospectus supplement is September 30, 2025. UNITED STATES SECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13A-16 OR 15D-16 UNDER THE SECURITIESEXCHANGE ACT OF 1934 For the month of September 2025 Commission File Number: 001-42684 RUBICO 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☒Form 40-F☐ INFORMATION CONTAINED IN THIS FORM 6-K REPORT Attached asExhibit 99.1to this report on Form 6-K (the “Report”) is Management's Discussion and Analysis of Financial Condition andResults of Operations and the unaudited interim condensed combined carve-out financial statements and related notes thereto for RubicoInc. (the "Company"), as of and for the six months ended June 30, 2025. Cautionary Note Regarding Forward-Looking Statements Matters discussed in this Report may constitute forward-looking statements. The Private Securities Litigation Reform Act of 1995 providessafe harbor protections for forward-looking statements in order to encourage companies to provide prospective information about theirbusiness. Forward-looking statements include statements concerning plans, objectives, goals, strategies, future events or performance, andunderlying assumptions and other statements, which are other than statements of historical facts, including statements regarding theCompany’s future financial performance. The Company desires to take advantage of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 and isincluding this cautionary statement in connection with this safe harbor legislation. The words “believe,” “anticipate,” “intends,” “estimate,”“forecast,”“project,”“plan,”“potential,”“may,”“should,”“expect,”“pending,”and similar expressions identify forward-lookingstatements. The forward-looking statements in this report are based upon various assumptions, many of which are based, in turn, upon furtherassumptions, including, without limitation, management's examination of historical operating trends, data contained in the Company’srecords, and other data available from third parties. Although the Company believes that these assumptions were reasonable when made,because these assumptions are inherently subject to significant uncertainties and contingencies which are difficult or impossible to predictand are beyond the Company’s control, the Company cannot assure you that it will achieve or accomplish these expectations, beliefs, orprojections. In addition to these assumptions, important factors that, in the Company’s view, could cause actual results to differ materially fromthose discussed in the forward-looking statements include, among other things: •the Company’s ability to maintain or develop new and existing customer relationships with major crude oil companies andmajor commodity traders, including its ability to enter into long-term charters for its vessels and those it may acquire in thefuture;•the Company’s future operating and financial results;•the Company’s future vessel acquisitions, its business strategy and expected and unexpected capital spending or operatingexpenses, including any dry-docking, crewing, bunker costs and insurance costs;•the Company’s financial condition and liquidity, including its ability to pay amounts that it owes and to obtain financing inthe future to fund capital expenditu