# EDGAR Filing Document

**Accession Number:** 0001951067
**File Stem:** 0001193125-25-227569
**Filing Date:** 2025-10
**Character Count:** 12023
**Document Hash:** de348ddcb02eac6d4bfb41dd1d465529
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-25-227569.hdr.sgml**: 20251002

**ACCESSION NUMBER**: 0001193125-25-227569

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13G/A

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20251002

**DATE AS OF CHANGE**: 20251002

**SUBJECT COMPANY**: 

**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:** SCHEDULE 13G/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-94125
- **FILM NUMBER:** 251367168

**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
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Pandora Consultants II SA
- **CENTRAL INDEX KEY:** 0002024451

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** D8
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G/A

**BUSINESS ADDRESS:**
- **STREET 1:** C/O STEALTH MARITIME CORPORATION S.A.
- **STREET 2:** 331, KIFISSIAS AVENUE
- **CITY:** KIFISSIA
- **STATE:** J3
- **ZIP:** PC 145 61
- **BUSINESS PHONE:** 302106250001

**MAIL ADDRESS:**
- **STREET 1:** C/O STEALTH MARITIME CORPORATION S.A.
- **STREET 2:** 331, KIFISSIAS AVENUE
- **CITY:** KIFISSIA
- **STATE:** J3
- **ZIP:** PC 145 61

### Attached PDF Documents

**Attachment 1:** `ck0000000000-ex99_1.pdf`

_No text found in this document._

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## SCHEDULE 13G

### Under the Securities Exchange Act of 1934

**(Amendment No. 1)**

**Issuer:** C3IS INC.

**Title of Class of Securities:** Common Stock, par value $0.01 per share

**CUSIP Number:** Y18284169

**Date of Event Which Requires Filing of this Statement:** 09/30/2025

**Check the appropriate box to designate the rule pursuant to which this Schedule is filed:**

- [ ] Rule 13d-1(b)

- [x] Rule 13d-1(c)

- [ ] Rule 13d-1(d)

---

| 1. | Names of Reporting Persons<br>Pandora Consultants II SA | Names of Reporting Persons<br>Pandora Consultants II SA |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>D8 | Citizenship or Place of Organization<br>D8 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>42940 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>42940 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>42940 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>42940 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>2.7% | Percent of Class Represented by Amount in Row (9)<br>2.7% |
| 12. | Type of Reporting Person (See Instructions)<br>CO | Type of Reporting Person (See Instructions)<br>CO |

**Comment for Type of Reporting Person:** (1)   Pandora Consultants II SA holds 42,940 of the reported shares. Mr. Nikolaos Vafias and his wife, Ms. Theano Vafias, control Pandora Consultants II SA and indirectly beneficially own the 42,940 shares held by Pandora Consultants II SA.

---

| 1. | Names of Reporting Persons<br>Theano Vafias | Names of Reporting Persons<br>Theano Vafias |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>J3 | Citizenship or Place of Organization<br>J3 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>42940 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>42940 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>42940 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>42940 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>2.7% | Percent of Class Represented by Amount in Row (9)<br>2.7% |
| 12. | Type of Reporting Person (See Instructions)<br>IN | Type of Reporting Person (See Instructions)<br>IN |

**Comment for Type of Reporting Person:** (1)   All reported shares are held by Pandora Consultants II SA. Ms. Theano Vafias and her husband, Mr. Nikolaos Vafias, control Pandora Consultants II SA and indirectly beneficially own the 42,940 shares held by Pandora Consultants II SA.

---

| 1. | Names of Reporting Persons<br>Nikolaos Vafias | Names of Reporting Persons<br>Nikolaos Vafias |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>J3 | Citizenship or Place of Organization<br>J3 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>6 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>42940 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>6 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>42940 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>42946 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>42946 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>2.7% | Percent of Class Represented by Amount in Row (9)<br>2.7% |
| 12. | Type of Reporting Person (See Instructions)<br>IN | Type of Reporting Person (See Instructions)<br>IN |

**Comment for Type of Reporting Person:** (1)   All reported shares are held by Pandora Consultants II SA. Ms. Theano Vafias and her husband, Mr. Nikolaos Vafias, control Pandora Consultants II SA and indirectly beneficially own the 42,940 shares held by Pandora Consultants II SA.

---

**Item 1(a). Name of Issuer:**
C3IS INC.

**Item 1(b). Address of Issuer's Principal Executive Offices:**
331 Kifissias Avenue Erithea 14561 Athens Greece

**Item 2(a). Name of Person Filing:**
This statement is being filed pursuant to a Joint Filing Agreement (attached as Exhibit 1 and incorporated herein by reference) between (i) Pandora Consultants II SA, a British Virgin Islands company, (ii) Nikolaos Vafias, an individual of Greek citizenship, and (iii) Theano Vafias, an individual of Greek citizenship (sometimes collectively referred to as the "Reporting Persons").

**Item 2(b). Address of Principal Business Office:**
Pandora Consultants II SA:
Kingston Chambers,
P.O. BOX 173, Road Town,
Tortola, BRITISH VIRGIN ISLANDS

Nikolaos Vafias:
Menandrou Street, 12, Flat 502
1066 Nicosia, Cyprus

Theano Vafias:
Menandrou Street, 12, Flat 502
1066 Nicosia, Cyprus

**Item 2(c). Citizenship:**
See Item 2(a) above.

**Item 2(d). Title of Class of Securities:**
Common Stock, par value $0.01 per share

**Item 2(e). CUSIP Number:**
Y18284169

**Item 3. If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:**

(a) [ ] Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).

(b) [ ] Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

(c) [ ] Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).

(d) [ ] Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8).

(e) [ ] An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);

(f) [ ] An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);

(g) [ ] A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);

(h) [ ] A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i) [ ] A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j) [ ] A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), if filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:

(k) [ ] Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).

**Item 4. Ownership:**

**(a) Amount beneficially owned:**

The information in Item 1 and Items 5 through 11 on the cover pages of this Schedule 13G is incorporated herein by reference.

**(b) Percent of class:**

—

**Item 5. Ownership of Five Percent or Less of a Class.**

[ ] If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following.

**Item 6. Ownership of More than 5 Percent on Behalf of Another Person.**

Not Applicable

**Item 7. Identification and Classification of the Subsidiary**

Not Applicable

**Item 8. Identification and Classification of Members of the Group**

Not Applicable

**Item 9. Notice of Dissolution of Group**

Not Applicable

**Item 10. Certification:**

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

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Pandora Consultants II SA**

**Date:** 10/02/2025

**By:** /s/ Nikolaos Vafias

**Name & Title:** Nikolaos Vafias, Director

**Theano Vafias**

**Date:** 10/02/2025

**By:** /s/ Theano Vafias

**Name & Title:** Theano Vafias

**Nikolaos Vafias**

**Date:** 10/02/2025

**By:** /s/ Nikolaos Vafias

**Name & Title:** Nikolaos Vafias