Imperial Petroleum Inc./Marshall Islands - 12 Dec 2025 SCHEDULE 13D/A Report for C3is Inc. Common Stock, par value $0.01 per share (CISS)

Filing Manager: Imperial Petroleum Inc./Marshall Islands
Reporting Manager: Imperial Petroleum Inc.
Security: C3is Inc. Common Stock, par value $0.01 per share
Symbol: CISS
Shares outstanding: 20.5M shares
Disclosed Ownership: 12.5M shares
Ownership: 61.1%
Form type: SCHEDULE 13D/A
Filing time: 15 Dec 2025, 06:05:17 UTC
Date of event: 12 Dec 2025
Previous filing: 10 Oct 2025
SEC: View on sec.gov

Reporting Managers (1)

Name	Ownership	Shares Owned	sole voting power	shared voting power	Signature	Title	CIK
Imperial Petroleum Inc.	61.1%	12.5M	12.5M	0	Harry N. Vafias	Chief Executive Officer	0001876581