SC 13D/A

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 2)^*

C3IS INC.

(Name of Issuer)

Common Stock, par value $0.01 per share

(Title of Class of Securities)

Y18284 201

(CUSIP Number)

Harry N. Vafias

c/o C3is Inc.

331 Kifissias Avenue

Erithrea 14561

Athens, Greece

011 30210 625 0001

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

September 16, 2024

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the  following box ☐.

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See § 240.13d-7 for other parties to whom copies are to be sent.

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

(Continued on following pages)

CUSIP No. Y18284 201 13D

1	NAME OF REPORTING PERSONS  Flawless Management Inc.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (see instructions)  (a) ☐  (b) ☐
3	SEC USE ONLY
4	SOURCE OF FUNDS (see instructions)  OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) or 2(e)  ☐
6	CITIZENSHIP OR PLACE OF ORGANIZATION  Republic of the Marshall Islands

NUMBER OF SHARES BENEFICIALLY  OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER  0
	8	SHARED VOTING POWER  74
	9	SOLE DISPOSITIVE POWER  0
	10	SHARED DISPOSITIVE POWER  74

11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON  74
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (see instructions)  ☐
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 11  0.001%
14	TYPE OF REPORTING PERSON (see instructions)  CO

CUSIP No. Y18284 201 13D

1	NAME OF REPORTING PERSONS  Arethusa Properties LTD
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (see instructions)  (a) ☐  (b) ☐
3	SEC USE ONLY
4	SOURCE OF FUNDS (see instructions)  OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) or 2(e)  ☐
6	CITIZENSHIP OR PLACE OF ORGANIZATION  British Virgin Islands

NUMBER OF SHARES BENEFICIALLY  OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER  0
	8	SHARED VOTING POWER  1,084,965
	9	SOLE DISPOSITIVE POWER  0
	10	SHARED DISPOSITIVE POWER  1,084,965

11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON  1,084,965
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (see instructions)  ☐
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 11  10.2%
14	TYPE OF REPORTING PERSON (see instructions)  CO

CUSIP No. Y18284 201 13D

1	NAME OF REPORTING PERSONS  Harry N. Vafias
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (see instructions)  (a) ☐  (b) ☐
3	SEC USE ONLY
4	SOURCE OF FUNDS (see instructions)  OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) or 2(e)  ☐
6	CITIZENSHIP OR PLACE OF ORGANIZATION  GREECE

NUMBER OF SHARES BENEFICIALLY  OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER  348,643*
	8	SHARED VOTING POWER  1,085,039
	9	SOLE DISPOSITIVE POWER  348,643*
	10	SHARED DISPOSITIVE POWER  1,085,039

11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON  1,433,682*
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (see instructions)  ☐
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 11  13.5%*
14	TYPE OF REPORTING PERSON (see instructions)  IN

* Includes 347,710 restricted shares of Common Stock outstanding as of the date hereof, of which 3,855 vest on November 6, 2024, 170,000 vest on September 16, 2025, 3,855 vest on November 6, 2025 and 170,000 vest on September 16, 2026. These shares remain subject to forfeiture if the time-based vesting conditions are not satisfied. Excludes 150,000 shares issuable upon exercise of unvested stock options, 75,000 of which vest on September 16, 2025 and 75,000 of which vest on September 16, 2026, subject to satisfaction of time-based vesting criteria.

AMENDMENT NO. 2 TO

STATEMENT ON SCHEDULE 13D

This Amendment No. 2 (this “Amendment No. 2”) to Schedule 13D (originally filed on May 20, 2024, as amended by Amendment No. 1 on June 24, 2024) relates to the common stock, par value $0.01 per share (“Common Stock”), of C3is Inc., a Marshall Islands corporation (the “Issuer”), and is being filed pursuant to a Joint Filing Agreement (attached as Exhibit 1 and incorporated herein by reference) by and between Flawless Management Inc., a Republic of the Marshall Islands corporation (“Flawless”), Arethusa Properties LTD, a British Virgin Islands company (“Arethusa”), and Harry N. Vafias in his personal capacity (sometimes collectively referred to as the “Reporting Persons”).

Information given in response to each item below shall be deemed incorporated by reference in all other items below. Unless indicated otherwise, all items left blank remain unchanged, and any items which are amended below are deemed to amend and update the existing items in the Schedule 13D.

All Common Stock share amounts reflect  the 1-for-100 reverse split of the Common Stock effected by the Issuer on April 11, 2024, at 11:59 p.m., Eastern time.

Item 3. Source and Amount of Funds or Other Consideration

Item 3 of the Statement is hereby amended by adding the following paragraphs to the end of Item 3:

On September 16, 2024, Mr. Vafias acquired, as compensatory awards, (1) 340,000 restricted shares of Common Stock with a vesting date of September 16, 2025 for 170,000 such shares and September 16, 2026 for 170,000 such shares, and (2) options exercisable to acquire 150,000 shares of Common Stock at an exercise price per share equal to $1.16, the closing price of the Common Stock on Nasdaq on September 16, 2024, 50% of which vest on September 16, 2025 and 50% of which vest on September 16, 2026.

Item 4. Purpose of Transaction.

The Reporting Persons acquired the securities described in this Schedule 13D for investment purposes and intend to review their investment in the Issuer on a continuing basis. Any Reporting Person may from time to time acquire additional securities of the Issuer, or retain or sell all or a portion of the shares then held by the Reporting Persons, in the open market, block trades, underwritten public offerings or privately negotiated transactions. Any actions any Reporting Person might undertake with respect to its investment in the Issuer may be made at any time and from time to time and will be dependent upon such Reporting Person’s review of numerous factors, including, but not limited to: ongoing evaluation of the Issuer’s business, financial condition, operations, prospects and strategic alternatives; price levels of the Issuer’s securities; general market, industry and economic conditions; the relative attractiveness of alternative business and investment opportunities; tax considerations; liquidity of the Issuer’s securities; and other factors and future developments.

Mr. Vafias serves as the Non-Executive Chairman of the Issuer and therefore regularly engages in discussions with management of the Issuer, the board of directors of the Issuer, other shareholders of the Issuer and other relevant parties, which discussions may include matters ranging from the operations and conduct of the Issuer’s business to considering or exploring extraordinary corporate transactions including the events listed in Items 4(a) through 4(j) of Schedule 13D. In connection with these discussions, the Reporting Persons may, either directly or through one or more affiliates, determine to take any available course of action or to take no course of action and may at any time and from time to time take steps to further or implement such course of action, including any of the events listed in Items 4(a) through 4(j) of Schedule 13D. Any action or actions the Reporting Persons may undertake with respect to their investment in the Issuer or the operations and conduct of the Issuer’s business will be dependent upon the Reporting Persons’ review of numerous factors, including those listed above, and the Reporting Persons specifically reserve the right to change their intentions, or to formulate plans and proposals, with respect to any or all of the matters described in this paragraph, subject to applicable law and regulations.

Item 5. Interest in Securities of the Issuer

Item 5 is hereby amended and restated as follows:

(a) See Items 11 and 13 on the cover pages to this Statement for the aggregate number and percentage of the class of Common Stock owned by each Reporting Person.

(b) Number of shares as to which each Reporting Person has:

i. Sole power to vote or to direct the vote: See Item 7 on cover pages to this Statement.

ii. Shared power to vote or to direct the vote: See Item 8 on cover pages to this Statement.

iii. Sole power to dispose or direct the disposition: See Item 9 on cover pages to this Statement.

iv. Shared power to dispose or direct the disposition: See Item 10 on cover pages to this Statement.

(c) Except as set forth in Item 3 to this Schedule, no transactions in the Company’s Common Stock by the Reporting Persons were effected in the past 60 days.

(d) No other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Common Stock beneficially owned by the Reporting Persons.

(e) Not applicable.

Item 7. Material to be Filed as Exhibits.

Item 7 is hereby amended to add the following exhibit:

Exhibit 1: Joint Filing Agreement, dated September 18, 2024, among Flawless Management Inc., Arethusa Properties LTD and Harry N. Vafias.

[The remainder of this page intentionally left blank]

SIGNATURE

After reasonable inquiry and to the best of the knowledge and belief of each of the undersigned, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

Dated: September 18, 2024

FLAWLESS MANAGEMENT INC.
By:	/s/ Harry N. Vafias
	Harry N. Vafias
	President
ARETHUSA PROPERTIES LTD.
By:	/s/ Harry N. Vafias
	Harry N. Vafias
	President
/s/ Harry N. Vafias
Harry N. Vafias

EX-99.1

EXHIBIT 1

JOINT FILING AGREEMENT

JOINT FILING AGREEMENT, dated as of September 18, 2024, between Flawless Management Inc., Arethusa Properties LTD and Harry N. Vafias (collectively, the “Joint Filers”).

WHEREAS, pursuant to Rule 13d-1(k) under the Securities Exchange  Act of 1934, as amended (the “Exchange Act”), the parties hereto desire to satisfy any filing obligation under Section 13(d) of the Exchange Act by a single joint filing;

NOW, THEREFORE, in consideration of the premises and the mutual covenants herein contained, the Joint Filers hereby agree and represent as follows:

1. Schedule 13D with respect to the Common Stock, par value $0.01 per share, of C3is Inc. (to which this Joint Filing Agreement is an exhibit) is filed on behalf of each of the Joint Filers.

2. Each of the Joint Filers is responsible for the timely filing of Schedule 13D and any amendments thereto, and for the completeness and accuracy of the information concerning such person contained therein, provided that each such person is not responsible for the completeness or accuracy of the information concerning the other persons making the filing, unless such person knows or has reason to believe that such information is inaccurate.

[Signature page to follow]

IN WITNESS WHEREOF, the undersigned have caused this Joint Filing Agreement to be duly executed and delivered as of the date first written above.

FLAWLESS MANAGEMENT INC.
By:	/s/ Harry N. Vafias
	Harry N. Vafias
	President
ARETHUSA PROPERTIES LTD.
By:	/s/ Harry N. Vafias
	Harry N. Vafias
	President
/s/ Harry N. Vafias
Harry N. Vafias