# EDGAR Filing Document

**Accession Number:** 0001943421
**File Stem:** 0001171843-25-007630
**Filing Date:** 2025-11
**Character Count:** 8017
**Document Hash:** 5814e0c8ded264a6050bc757558d7a53
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001171843-25-007630.hdr.sgml**: 20251126

**ACCESSION NUMBER**: 0001171843-25-007630

**CONFORMED SUBMISSION TYPE**: 424B3

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20251126

**DATE AS OF CHANGE**: 20251126

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Rubico Inc.
- **CENTRAL INDEX KEY:** 0001943421
- **STANDARD INDUSTRIAL CLASSIFICATION:** WATER TRANSPORTATION [4400]
- **ORGANIZATION NAME:** 01 Energy & Transportation
- **EIN:** 000000000
- **STATE OF INCORPORATION:** 1T
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 424B3
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-290426
- **FILM NUMBER:** 251530537

**BUSINESS ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** VAS SOFIAS 1 & MEG. ALEXANDROU
- **CITY:** ATHENS
- **PROVINCE COUNTRY:** J3
- **BUSINESS PHONE:** 30 2108128180

**MAIL ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** VAS SOFIAS 1 & MEG. ALEXANDROU
- **CITY:** ATHENS
- **PROVINCE COUNTRY:** J3

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Central Tactical Acquisitions Inc.
- **DATE OF NAME CHANGE:** 20220818

**Filed Pursuant to Rule 424(b)(3)**

**Registration No. 333-290426**

**PROSPECTUS SUPPLEMENT NO. 3**

**(TO PROSPECTUS DATED NOVEMBER 4, 2025)**

**<br> 12,315,270 Units, Each Unit Consisting of One Common Share or One Pre-funded Warrant to Purchase One Common Share and One Class A Warrant to Purchase One Common Share**

**615,763 Representative Warrants**

**(and up to 12,315,270 Common Shares Underlying the Pre-funded Warrants, up to 49,261,080 Common Shares Underlying the Class A Warrants and up to 2,463,052 Common Shares Underlying the Representative Warrants)**

**RUBICO INC.**

This is a supplement (the "Prospectus Supplement") to the prospectus, dated November 4, 2025 (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 No. 333-290426), as amended 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 the Company's Report on Form 6-K, furnished to the U.S. Securities and Exchange Commission (the "Commission") on November 26, 2025 (the "Form 6-K"). Accordingly, the Form 6-K is 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 the extent 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 any amendments or supplements to it.

**Investing in our securities involves a high degree of risk. See "<u>Risk Factors</u>" beginning on page 12 of the Prospectus for a discussion of information that 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 is truthful or complete. Any representation to the contrary is a criminal offense.**

**The date of this prospectus supplement is November 26, 2025.**

**UNITED STATES SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

**FORM 6-K**

**REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13A-16 OR 15D-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934**

For the month of November 2025

Commission File Number: 001-42684

## RUBICO INC.
(Translation of registrant's name into English)

**20 Iouliou Kaisara Str<br> 19002 Paiania** 

**Athens, 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**

On November 25, 2025, the Registrant issued a press release, a copy of which is attached hereto as [Exhibit 99.1](#a_002).

**SIGNATURES**

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

---

| | |
|:---|:---|
|  | **Rubico Inc.** |
| Date: November 26, 2025 | <u><u>By: /s/ Nikolaos Papastratis</u></u> |
|  | Nikolaos Papastratis |
|  | Chief Financial Officer |

---

**EXHIBIT 99.1**

![](logo.jpg)

**Rubico Inc. Announces Time Charter Extensions and Contracted Revenue Backlog of $120.8 Million**

ATHENS, Greece, November 25, 2025 (GLOBE NEWSWIRE) -- Rubico Inc. (NASDAQ: RUBI) (the "Company"), an international owner and operator of modern, fuel efficient "ECO" tanker vessels, announced today that it entered into agreements with the time charterer of both its vessels to extend their time charter employment.

Specifically, both vessels will continue earning a gross daily hire rate of $32,850 until 11 January 2027 and thereafter, and for 4 years, they earn a gross daily hire rate of $29,990.

All other terms will remain as per the current time charter contracts, including the charterer's option to extend each time charter for two additional years at a gross daily rate of $34,750 for the first optional year and $36,750 for the second optional year. Following this development, the total contracted revenue backlog since the latest reported period stands at $120.8 million.

**About the Company**

Rubico Inc. is a global provider of shipping transportation services specializing in the ownership of vessels. The Company is an international owner and operator of two modern, fuel efficient, eco 157,000 dwt Suezmax tankers.

The Company is incorporated under the laws of the Republic of the Marshall Islands and has executive offices in Athens, Greece. The Company's common shares trade on the Nasdaq Capital Market under the symbol "RUBI".

Please visit the Company's website at: <u>https://rubicoinc.com/</u>

**Forward-Looking Statements**

Matters discussed in this press release may constitute forward-looking statements. The Private Securities Litigation Reform Act of 1995 provides safe harbor protections for forward-looking statements in order to encourage companies to provide prospective information about their business. Forward-looking statements include statements concerning plans, objectives, goals, strategies, future events or performance, and underlying assumptions and other statements, which are other than statements of historical facts, including statements regarding the employment of the Company's vessels.

The Company desires to take advantage of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 and is including 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-looking statements. The forward-looking statements in this press release are based upon various assumptions, many of which are based, in turn, upon further assumptions, including without limitation, our management's examination of historical operating trends, data contained in our records and other data available from third parties. Although we believe that these assumptions were reasonable when made, because these assumptions are inherently subject to significant uncertainties and contingencies which are difficult or impossible to predict and are beyond our control, we cannot assure you that we will achieve or accomplish these expectations, beliefs or projections.

**For further information please contact:**<br> Nikolaos Papastratis<br> Chief Financial Officer<br> Rubico Inc.<br> Tel: +30 210 812 8107<br> Email: npapastratis@rubicoinc.com