C3is Inc. SEC EDGAR Filings (CIK 0001951067)

SEC EDGAR filings, ownership reports, and insider transactions for C3is Inc..

Symbol
CISS on Nasdaq
Industry
Deep Sea Foreign Transportation Of Freight (Office Of Energy & Transportation)
Business address
331 Kifissias Avenue, Erithrea, Athens, Greece, 14561
State of incorporation
Marshall Islands
Fiscal year end
31 December
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C3is Inc. has filed 217 SEC EDGAR filings since 07 Dec 2022

Latest Filings

Recent SEC filings for C3is Inc. including 424B3, 6-K, SCHEDULE 13G/A and more.

Form type Document Filing Description Filing date Reporting date File number(s)
424B3 Open 424B3 document View SEC filing for 424B3 424B3 22 Jan 2026 333-290011
424B3 Open 424B3 document View SEC filing for 424B3 424B3 22 Jan 2026 333-272939
424B3 Open 424B3 document View SEC filing for 424B3 424B3 22 Jan 2026 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 22 Jan 2026 333-276430
6-K Open 6-K document View SEC filing for 6-K 6-K 22 Jan 2026 22 Jan 2026 001-41717
424B3 Open 424B3 document View SEC filing for 424B3 424B3 20 Jan 2026 333-290011
424B3 Open 424B3 document View SEC filing for 424B3 424B3 20 Jan 2026 333-272939
424B3 Open 424B3 document View SEC filing for 424B3 424B3 20 Jan 2026 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 20 Jan 2026 333-276430
6-K Open 6-K document View SEC filing for 6-K 6-K 20 Jan 2026 20 Jan 2026 001-41717
SCHEDULE 13G/A Open SCHEDULE 13G/A document View SEC filing for SCHEDULE 13G/A 14 Jan 2026 005-94125
SCHEDULE 13G/A Open SCHEDULE 13G/A document View SEC filing for SCHEDULE 13G/A 13 Jan 2026 005-94125
SCHEDULE 13G Open SCHEDULE 13G document View SEC filing for SCHEDULE 13G 08 Jan 2026 005-94125
SCHEDULE 13D/A Open SCHEDULE 13D/A document View SEC filing for SCHEDULE 13D/A 30 Dec 2025 005-94125
424B3 Open 424B3 document View SEC filing for 424B3 424B3 19 Dec 2025 333-290011
424B3 Open 424B3 document View SEC filing for 424B3 424B3 19 Dec 2025 333-272939
424B3 Open 424B3 document View SEC filing for 424B3 424B3 19 Dec 2025 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 19 Dec 2025 333-276430
6-K Open 6-K document View SEC filing for 6-K 6-K 19 Dec 2025 19 Dec 2025 001-41717
EFFECT Open EFFECT document View SEC filing for EFFECT 18 Dec 2025 333-276868
EFFECT Open EFFECT document View SEC filing for EFFECT 18 Dec 2025 333-276430
EFFECT Open EFFECT document View SEC filing for EFFECT 18 Dec 2025 333-272939
SCHEDULE 13G Open SCHEDULE 13G document View SEC filing for SCHEDULE 13G 18 Dec 2025 005-94125
SCHEDULE 13G Open SCHEDULE 13G document View SEC filing for SCHEDULE 13G 17 Dec 2025 005-94125
POS AM Open POS AM document View SEC filing for POS AM POS AM 15 Dec 2025 333-272939
POS AM Open POS AM document View SEC filing for POS AM POS AM 15 Dec 2025 333-276430
POS AM Open POS AM document View SEC filing for POS AM POS AM 15 Dec 2025 333-276868
SCHEDULE 13D/A Open SCHEDULE 13D/A document View SEC filing for SCHEDULE 13D/A 15 Dec 2025 005-94125
6-K Open 6-K document View SEC filing for 6-K 6-K 12 Dec 2025 12 Dec 2025 001-41717
424B4 Open 424B4 document View SEC filing for 424B4 424B4 11 Dec 2025 333-290011
EFFECT Open EFFECT document View SEC filing for EFFECT 10 Dec 2025 333-290011
F-1/A Open F-1/A document View SEC filing for F-1/A F-1/A 05 Dec 2025 333-290011
EFFECT Open EFFECT document View SEC filing for EFFECT 21 Nov 2025 333-276868
6-K Open 6-K document View SEC filing for 6-K 6-K 18 Nov 2025 18 Nov 2025 001-41717
SCHEDULE 13G/A Open SCHEDULE 13G/A document View SEC filing for SCHEDULE 13G/A 14 Nov 2025 005-94125
F-1/A Open F-1/A document View SEC filing for F-1/A F-1/A 03 Nov 2025 333-290011
SCHEDULE 13G Open SCHEDULE 13G document View SEC filing for SCHEDULE 13G 28 Oct 2025 005-94125
SCHEDULE 13D/A Open SCHEDULE 13D/A document View SEC filing for SCHEDULE 13D/A 10 Oct 2025 005-94125
SCHEDULE 13D/A Open SCHEDULE 13D/A document View SEC filing for SCHEDULE 13D/A 10 Oct 2025 005-94125
6-K Open 6-K document View SEC filing for 6-K 6-K 09 Oct 2025 09 Oct 2025 001-41717
424B5 Open 424B5 document View SEC filing for 424B5 424B5 09 Oct 2025 333-285135
SCHEDULE 13G/A Open SCHEDULE 13G/A document View SEC filing for SCHEDULE 13G/A 02 Oct 2025 005-94125
SCHEDULE 13D/A Open SCHEDULE 13D/A document View SEC filing for SCHEDULE 13D/A 01 Oct 2025 005-94125
POS AM Open POS AM document View SEC filing for POS AM POS AM 01 Oct 2025 333-276868
POS AM Open POS AM document View SEC filing for POS AM POS AM 01 Oct 2025 333-272939
POS AM Open POS AM document View SEC filing for POS AM POS AM 01 Oct 2025 333-276430
SCHEDULE 13G/A Open SCHEDULE 13G/A document View SEC filing for SCHEDULE 13G/A 29 Sep 2025 005-94125
6-K Open 6-K document | Open XBRL data View SEC filing for 6-K 6-K 29 Sep 2025 30 Jun 2025 001-41717
SCHEDULE 13G Open SCHEDULE 13G document View SEC filing for SCHEDULE 13G 24 Sep 2025 005-94125
F-1 Open F-1 document | Open XBRL data View SEC filing for F-1 F-1 03 Sep 2025 333-290011
424B3 Open 424B3 document View SEC filing for 424B3 424B3 02 Sep 2025 333-272939
424B3 Open 424B3 document View SEC filing for 424B3 424B3 02 Sep 2025 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 02 Sep 2025 333-276430
6-K Open 6-K document View SEC filing for 6-K 6-K 02 Sep 2025 02 Sep 2025 001-41717
6-K Open 6-K document View SEC filing for 6-K 6-K 29 Aug 2025 29 Aug 2025 001-41717
DRS Open DRS document View SEC filing for DRS 21 Jul 2025 377-08236
6-K Open 6-K document View SEC filing for 6-K 6-K 25 Jun 2025 25 Jun 2025 001-41717
424B3 Open 424B3 document View SEC filing for 424B3 424B3 16 May 2025 333-276430
424B3 Open 424B3 document View SEC filing for 424B3 424B3 16 May 2025 333-272939
424B3 Open 424B3 document View SEC filing for 424B3 424B3 16 May 2025 333-276868
6-K Open 6-K document View SEC filing for 6-K 6-K 16 May 2025 16 May 2025 001-41717
EFFECT Open EFFECT document View SEC filing for EFFECT 05 May 2025 333-276868
EFFECT Open EFFECT document View SEC filing for EFFECT 05 May 2025 333-276430
EFFECT Open EFFECT document View SEC filing for EFFECT 05 May 2025 333-272939
POS AM Open POS AM document View SEC filing for POS AM POS AM 30 Apr 2025 333-276430
POS AM Open POS AM document View SEC filing for POS AM POS AM 30 Apr 2025 333-272939
POS AM Open POS AM document View SEC filing for POS AM POS AM 30 Apr 2025 333-276868
20-F Open 20-F document | Open XBRL data View SEC filing for 20-F 20-F 28 Apr 2025 31 Dec 2024 001-41717
SCHEDULE 13D/A Open SCHEDULE 13D/A document View SEC filing for SCHEDULE 13D/A 15 Apr 2025 005-94125
424B3 Open 424B3 document View SEC filing for 424B3 424B3 04 Apr 2025 333-272939
424B3 Open 424B3 document View SEC filing for 424B3 424B3 04 Apr 2025 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 04 Apr 2025 333-276430
6-K Open 6-K document View SEC filing for 6-K 6-K 04 Apr 2025 04 Apr 2025 001-41717
424B3 Open 424B3 document View SEC filing for 424B3 424B3 02 Apr 2025 333-272939
424B3 Open 424B3 document View SEC filing for 424B3 424B3 02 Apr 2025 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 02 Apr 2025 333-276430
6-K Open 6-K document View SEC filing for 6-K 6-K 02 Apr 2025 02 Apr 2025 001-41717
424B3 Open 424B3 document View SEC filing for 424B3 424B3 12 Mar 2025 333-272939
424B3 Open 424B3 document View SEC filing for 424B3 424B3 12 Mar 2025 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 12 Mar 2025 333-276430
6-K Open 6-K document View SEC filing for 6-K 6-K 12 Mar 2025 12 Mar 2025 001-41717
EFFECT Open EFFECT document View SEC filing for EFFECT 06 Mar 2025 333-285135
CORRESP Open CORRESP document View SEC filing for CORRESP 04 Mar 2025
UPLOAD Open UPLOAD document View SEC filing for UPLOAD 03 Mar 2025 333-285135
F-3 Open F-3 document View SEC filing for F-3 F-3 21 Feb 2025 333-285135
6-K Open 6-K document View SEC filing for 6-K 6-K 21 Feb 2025 21 Feb 2025 001-41717
6-K Open 6-K document View SEC filing for 6-K 6-K 18 Feb 2025 18 Feb 2025 001-41717
SCHEDULE 13G/A Open SCHEDULE 13G/A document View SEC filing for SCHEDULE 13G/A 14 Feb 2025 005-94125
SCHEDULE 13D/A Open SCHEDULE 13D/A document View SEC filing for SCHEDULE 13D/A 14 Jan 2025 005-94125
424B3 Open 424B3 document View SEC filing for 424B3 424B3 02 Jan 2025 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 02 Jan 2025 333-276430
424B3 Open 424B3 document View SEC filing for 424B3 424B3 02 Jan 2025 333-272939
6-K Open 6-K document View SEC filing for 6-K 6-K 02 Jan 2025 02 Jan 2025 001-41717
EFFECT Open EFFECT document View SEC filing for EFFECT 13 Dec 2024 333-276430
EFFECT Open EFFECT document View SEC filing for EFFECT 13 Dec 2024 333-276868
EFFECT Open EFFECT document View SEC filing for EFFECT 13 Dec 2024 333-272939
POS AM Open POS AM document View SEC filing for POS AM POS AM 10 Dec 2024 333-272939
POS AM Open POS AM document View SEC filing for POS AM POS AM 10 Dec 2024 333-276868
POS AM Open POS AM document View SEC filing for POS AM POS AM 10 Dec 2024 333-276430
424B3 Open 424B3 document View SEC filing for 424B3 424B3 19 Nov 2024 333-272939
424B3 Open 424B3 document View SEC filing for 424B3 424B3 19 Nov 2024 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 19 Nov 2024 333-276430
6-K Open 6-K document View SEC filing for 6-K 6-K 19 Nov 2024 19 Nov 2024 001-41717
424B3 Open 424B3 document View SEC filing for 424B3 424B3 30 Sep 2024 333-272939
424B3 Open 424B3 document View SEC filing for 424B3 424B3 30 Sep 2024 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 30 Sep 2024 333-276430
6-K Open 6-K document | Open XBRL data View SEC filing for 6-K 6-K 30 Sep 2024 30 Jun 2024 001-41717
SC 13D/A Open SC 13D/A document View SEC filing for SC 13D/A SC 13D/A 18 Sep 2024 005-94125
6-K Open 6-K document View SEC filing for 6-K 6-K 30 Aug 2024 30 Aug 2024 001-41717
6-K Open 6-K document View SEC filing for 6-K 6-K 23 Aug 2024 23 Aug 2024 001-41717
SC 13D/A Open SC 13D/A document View SEC filing for SC 13D/A SC 13D/A 24 Jun 2024 005-94125
424B3 Open 424B3 document View SEC filing for 424B3 424B3 28 May 2024 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 28 May 2024 333-276430
424B3 Open 424B3 document View SEC filing for 424B3 424B3 28 May 2024 333-272939
6-K Open 6-K document View SEC filing for 6-K 6-K 28 May 2024 28 May 2024 001-41717
SC 13G Open SC 13G document View SEC filing for SC 13G SC 13G 24 May 2024 005-94125
SC 13D Open SC 13D document View SEC filing for SC 13D SC 13D 20 May 2024 005-94125
EFFECT Open EFFECT document View SEC filing for EFFECT 08 May 2024 333-272939
EFFECT Open EFFECT document View SEC filing for EFFECT 08 May 2024 333-276430
EFFECT Open EFFECT document View SEC filing for EFFECT 08 May 2024 333-276868
SC 13D/A Open SC 13D/A document View SEC filing for SC 13D/A SC 13D/A 01 May 2024 005-94125
POS AM Open POS AM document View SEC filing for POS AM POS AM 01 May 2024 333-276868
POS AM Open POS AM document View SEC filing for POS AM POS AM 01 May 2024 333-276430
POS AM Open POS AM document View SEC filing for POS AM POS AM 01 May 2024 333-272939
20-F Open 20-F document | Open XBRL data View SEC filing for 20-F 20-F 30 Apr 2024 31 Dec 2023 001-41717
424B3 Open 424B3 document View SEC filing for 424B3 424B3 12 Apr 2024 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 12 Apr 2024 333-276430
424B3 Open 424B3 document View SEC filing for 424B3 424B3 12 Apr 2024 333-272939
6-K Open 6-K document View SEC filing for 6-K 6-K 12 Apr 2024 12 Apr 2024 001-41717
424B3 Open 424B3 document View SEC filing for 424B3 424B3 12 Apr 2024 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 12 Apr 2024 333-276430
424B3 Open 424B3 document View SEC filing for 424B3 424B3 12 Apr 2024 333-272939
6-K Open 6-K document View SEC filing for 6-K 6-K 12 Apr 2024 12 Apr 2024 001-41717
424B3 Open 424B3 document View SEC filing for 424B3 424B3 26 Mar 2024 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 26 Mar 2024 333-276430
424B3 Open 424B3 document View SEC filing for 424B3 424B3 26 Mar 2024 333-272939
6-K Open 6-K document View SEC filing for 6-K 6-K 26 Mar 2024 26 Mar 2024 001-41717
SC 13G Open SC 13G document View SEC filing for SC 13G SCHEDULE 13G 25 Mar 2024 005-94125
SC 13D/A Open SC 13D/A document View SEC filing for SC 13D/A SC 13D/A 20 Mar 2024 005-94125
424B3 Open 424B3 document View SEC filing for 424B3 424B3 19 Mar 2024 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 19 Mar 2024 333-276430
424B3 Open 424B3 document View SEC filing for 424B3 424B3 19 Mar 2024 333-272939
6-K Open 6-K document View SEC filing for 6-K 6-K 19 Mar 2024 19 Mar 2024 001-41717
424B3 Open 424B3 document View SEC filing for 424B3 424B3 15 Mar 2024 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 15 Mar 2024 333-276430
424B3 Open 424B3 document View SEC filing for 424B3 424B3 15 Mar 2024 333-272939
6-K Open 6-K document View SEC filing for 6-K 6-K 15 Mar 2024 15 Mar 2024 001-41717
424B4 Open 424B4 document View SEC filing for 424B4 424B4 15 Mar 2024 333-276868
EFFECT Open EFFECT document View SEC filing for EFFECT 14 Mar 2024 333-276868
CORRESP Open CORRESP document View SEC filing for CORRESP 14 Mar 2024
CORRESP Open CORRESP document View SEC filing for CORRESP 14 Mar 2024
CORRESP Open CORRESP document View SEC filing for CORRESP 14 Mar 2024
CORRESP Open CORRESP document View SEC filing for CORRESP 14 Mar 2024
CORRESP Open CORRESP document View SEC filing for CORRESP 11 Mar 2024
CORRESP Open CORRESP document View SEC filing for CORRESP 11 Mar 2024
CORRESP Open CORRESP document View SEC filing for CORRESP 23 Feb 2024
F-1/A Open F-1/A document View SEC filing for F-1/A F-1/A 23 Feb 2024 333-276868
UPLOAD Open UPLOAD document View SEC filing for UPLOAD 22 Feb 2024 333-276868
424B3 Open 424B3 document View SEC filing for 424B3 424B3 22 Feb 2024 333-276430
424B3 Open 424B3 document View SEC filing for 424B3 424B3 22 Feb 2024 333-272939
6-K Open 6-K document View SEC filing for 6-K FORM 6-K 22 Feb 2024 22 Feb 2024 001-41717
SC 13G Open SC 13G document View SEC filing for SC 13G 13-G 09 Feb 2024 005-94125
F-1 Open F-1 document View SEC filing for F-1 F-1 05 Feb 2024 333-276868
SC 13G Open SC 13G document View SEC filing for SC 13G SCHEDULE 13G 29 Jan 2024 005-94125
SC 13G Open SC 13G document View SEC filing for SC 13G SCHEDULE 13G 29 Jan 2024 005-94125
SC 13D/A Open SC 13D/A document View SEC filing for SC 13D/A SC 13D/A 24 Jan 2024 005-94125
SC 13D/A Open SC 13D/A document View SEC filing for SC 13D/A SC 13D/A 24 Jan 2024 005-94125
424B3 Open 424B3 document View SEC filing for 424B3 424B3 23 Jan 2024 333-272939
6-K Open 6-K document View SEC filing for 6-K 6-K 23 Jan 2024 23 Jan 2024 001-41717
424B4 Open 424B4 document View SEC filing for 424B4 424B4 22 Jan 2024 333-276430
F-1MEF Open F-1MEF document View SEC filing for F-1MEF F-1MEF 19 Jan 2024 333-276597
EFFECT Open EFFECT document View SEC filing for EFFECT 18 Jan 2024 333-276430
CORRESP Open CORRESP document View SEC filing for CORRESP 17 Jan 2024
CORRESP Open CORRESP document View SEC filing for CORRESP 17 Jan 2024
UPLOAD Open UPLOAD document View SEC filing for UPLOAD 16 Jan 2024 333-276430
F-1 Open F-1 document View SEC filing for F-1 F-1 08 Jan 2024 333-276430
SC 13D Open SC 13D document View SEC filing for SC 13D SC 13D 16 Nov 2023 005-94125
424B3 Open 424B3 document View SEC filing for 424B3 424B3 06 Nov 2023 333-272939
6-K Open 6-K document View SEC filing for 6-K 6-K 06 Nov 2023 06 Nov 2023 001-41717
DRS Open DRS document View SEC filing for DRS 29 Sep 2023 377-06902
424B3 Open 424B3 document View SEC filing for 424B3 424B3 29 Sep 2023 333-272939
6-K Open 6-K document View SEC filing for 6-K 6-K 29 Sep 2023 29 Sep 2023 001-41717
6-K Open 6-K document View SEC filing for 6-K 6-K 08 Sep 2023 08 Sep 2023 001-41717
424B3 Open 424B3 document View SEC filing for 424B3 424B3 25 Aug 2023 333-272939
6-K Open 6-K document View SEC filing for 6-K 6-K 25 Aug 2023 25 Aug 2023 001-41717
SC 13D Open SC 13D document View SEC filing for SC 13D SC 13D 28 Jul 2023 005-94125
S-8 Open S-8 document View SEC filing for S-8 S-8 18 Jul 2023 333-273306
424B3 Open 424B3 document View SEC filing for 424B3 424B3 17 Jul 2023 333-272939
6-K Open 6-K document View SEC filing for 6-K 6-K 17 Jul 2023 17 Jul 2023 001-41717
424B3 Open 424B3 document View SEC filing for 424B3 424B3 05 Jul 2023 333-272939
6-K Open 6-K document View SEC filing for 6-K 6-K 05 Jul 2023 05 Jul 2023 001-41717
424B4 Open 424B4 document View SEC filing for 424B4 424B4 03 Jul 2023 333-272939
EFFECT Open EFFECT document View SEC filing for EFFECT 30 Jun 2023 333-272939
CORRESP Open CORRESP document View SEC filing for CORRESP 28 Jun 2023
CORRESP Open CORRESP document View SEC filing for CORRESP 28 Jun 2023
F-1 Open F-1 document View SEC filing for F-1 F-1 26 Jun 2023 333-272939
UPLOAD Open UPLOAD document View SEC filing for UPLOAD 26 Jun 2023
6-K Open 6-K document View SEC filing for 6-K 6-K 23 Jun 2023 23 Jun 2023 001-41717
DRS Open DRS document View SEC filing for DRS 14 Jun 2023 377-06747
EFFECT Open EFFECT document View SEC filing for EFFECT 12 Jun 2023 333-271228
424B1 Open 424B1 document View SEC filing for 424B1 424B1 12 Jun 2023 333-271228
CERT Open CERT document View SEC filing for CERT 12 Jun 2023 001-41717
CORRESP Open CORRESP document View SEC filing for CORRESP 08 Jun 2023
8-A12B Open 8-A12B document View SEC filing for 8-A12B 8-A12B 08 Jun 2023 001-41717
CORRESP Open CORRESP document View SEC filing for CORRESP 06 Jun 2023
F-1/A Open F-1/A document View SEC filing for F-1/A F-1/A 06 Jun 2023 333-271228
UPLOAD Open UPLOAD document View SEC filing for UPLOAD 01 Jun 2023
CORRESP Open CORRESP document View SEC filing for CORRESP 17 May 2023
F-1/A Open F-1/A document View SEC filing for F-1/A F-1/A 17 May 2023 333-271228
UPLOAD Open UPLOAD document View SEC filing for UPLOAD 28 Apr 2023
CORRESP Open CORRESP document View SEC filing for CORRESP 12 Apr 2023
F-1 Open F-1 document View SEC filing for F-1 F-1 12 Apr 2023 333-271228
UPLOAD Open UPLOAD document View SEC filing for UPLOAD 13 Feb 2023
DRSLTR Open DRSLTR document View SEC filing for DRSLTR 25 Jan 2023
DRS/A Open DRS/A document View SEC filing for DRS/A 25 Jan 2023 377-06490
UPLOAD Open UPLOAD document View SEC filing for UPLOAD 03 Jan 2023
DRS Open DRS document View SEC filing for DRS 07 Dec 2022 377-06490

About this filer

C3is Inc. files with the SEC under CIK 0001951067. This page aggregates EDGAR filings and related ownership activity.

Industry: Deep Sea Foreign Transportation Of Freight.

FAQ

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