# EDGAR Filing Document

**Accession Number:** 0001951067
**File Stem:** 0001193125-26-016737
**Filing Date:** 2026-1
**Character Count:** 3647
**Document Hash:** 33bb9b7928a1360e97bcb0315ccad22e
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-016737.hdr.sgml**: 20260120

**ACCESSION NUMBER**: 0001193125-26-016737

**CONFORMED SUBMISSION TYPE**: 6-K

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260120

**FILED AS OF DATE**: 20260120

**DATE AS OF CHANGE**: 20260120

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** C3is Inc.
- **CENTRAL INDEX KEY:** 0001951067
- **STANDARD INDUSTRIAL CLASSIFICATION:** DEEP SEA FOREIGN TRANSPORTATION OF FREIGHT [4412]
- **ORGANIZATION NAME:** 01 Energy & Transportation
- **EIN:** 000000000
- **STATE OF INCORPORATION:** 1T
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 6-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-41717
- **FILM NUMBER:** 26543563

**BUSINESS ADDRESS:**
- **STREET 1:** 331 KIFISSIAS AVENUE
- **STREET 2:** ERITHREA
- **CITY:** ATHENS
- **STATE:** J3
- **ZIP:** 14561
- **BUSINESS PHONE:** 011-30-210-625-0001

**MAIL ADDRESS:**
- **STREET 1:** 331 KIFISSIAS AVENUE
- **STREET 2:** ERITHREA
- **CITY:** ATHENS
- **STATE:** J3
- **ZIP:** 14561

**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 January 2026** 

**Commission File Number 001-41717** 

## C3IS INC.
**(Translation of registrant's name into English)** 

**331 Kifissias, Avenue Kifissia 14561 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** 

**Vessel Acquisition Agreement** 

C3is Inc. (the "Company") has entered into an agreement to acquire a 2011 South Korean-built product tanker with 47,203 deadweight tons (dwt) capacity for a purchase price of $22.9 million, from an entity affiliated with Brave Maritime Corp Inc. The transaction with Brave Maritime, which is affiliated with members of the Vafias family, was approved by the independent directors of the Company, which obtained independent valuations of the vessel, and used the average price of these valuations.

The vessel is expected to be delivered between Q1 and Q2 2026. The Company has the option to pay for the vessel one year after the date of the purchase agreement, without interest.

Following this vessel delivery, and assuming no further acquisitions or dispositions other than the pending product tanker acquisition previously announced, the Company's fleet will total 6 vessels, three Handysize drybulk carriers with a total capacity of 97,664 dwt, an Aframax oil tanker with a capacity of approximately 115,800 dwt and two product tankers with a capacity of approximately 97,203 dwt, resulting in a fleet total capacity of 310,667 dwt.

\*\*\*\*\*

This report on Form 6-K is hereby incorporated by reference into the Company's Registration Statement on Form S-8 (Reg. No. 333-273306) filed with the Securities and Exchange Commission on July 18, 2023 and Registration Statement on Form F-3 (Reg. No. 333- 285135) filed with the Securities and Exchange Commission on February 21, 2025.

------

**SIGNATURES** 

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

Date: January 20, 2026

---

| | |
|:---|:---|
| **C3IS INC.** | **C3IS INC.** |
| By: | /s/ Nina Pyndiah |
| Name: | Nina Pyndiah |
| Title: | Chief Financial Officer |

---