Beneficial Ownership Report · SCHEDULE 13G/A
C3is Inc.
CISSNASDAQEQUITYCurrent
Beneficial Ownership Report
Structured filing — SCHEDULE 13G/A
primary_doc.xml
Amendment · This filing reports the amendment as submitted.
Subject company
- Company
- C3is Inc.
- Company CIK
- 0001951067
- Street
- 331 KIFISSIAS AVENUE
- City
- ATHENS
- State / country code
- J3
- Postal code
- 14561
Statement details
- Amendment number
- 2
- Security class
- Common Stock, par value $0.01 per share
- Event date
- 08/26/2026
- Rule designation
- Rule 13d-1(c)
Reporting person 1
- Name
- Alta Partners LLC
- Citizenship / organization
- NY
- Reporting person type
- OO
- Aggregate amount owned
- 46,773.00
- Percent of class
- 3.1
- Sole voting power
- 46,773.00
- Shared voting power
- 0.00
- Sole dispositive power
- 46,773.00
- Shared dispositive power
- 0.00
Item 1
Issuer
C3is Inc.
Principal executive office address
331 KIFISSIAS AVENUE, ATHENS, GREECE, 14561.
Item 2
Citizenship
New York Limited Liability Company
Filing person
Alta Partners LLC
Principal business or residence address
1205 Franklin Avenue Garden City, New York 11530
Item 3
Not applicable indication
Y
Item 4
Percent of class
3.072%
Amount beneficially owned
46,773 shares, consisting of 12,000 shares of Common Stock and 34,773 shares issuable upon exercise of warrants held by the Reporting Person.
Sole voting power
46,773
Shared voting power
0
Sole dispositive power
46,773
Shared dispositive power
0
Item 5
Ownership of 5% or less
Y
Item 6
Not applicable indication
Y
Item 7
Not applicable indication
Y
Item 8
Not applicable indication
Y
Item 9
Not applicable indication
Y
Item 10
Not applicable indication
N
Certifications
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.
Signature 1
- Reporting person
- Alta Partners LLC
- Signed
- /s/ Steven Cohen
- Title
- Steven Cohen, Managing Member
- Date
- 10/05/2026
Company context
We are a provider of international seaborne transportation services to drybulk charterers, including major national and private industrial users, commodity producers and traders. As of the date of this prospectus, we own and operate a fleet of five vessels, comprising three drybulk carriers that transport major bulks such as iron ore, coal and grains, and minor bulks such as bauxite, phosphate and fertilizers, an Aframax crude oil tanker that transports crude oil and a product tanker that transports refined petroleum products. The total cargo carrying capacity of our fleet is 260,671 dwt. On a pro forma basis following the delivery of one additional MR product tanker that we have agreed to acquire, with expected delivery in the third quarter of 2026, our fleet will consist of six vessels: three Handysize dry bulk carriers, one Aframax tanker, and two MR product tankers, with a total carrying capacity of approximately 311,431 dwt.