# EDGAR Filing Document

**Accession Number:** 0001729638
**File Stem:** 0001729638-25-000006
**Filing Date:** 2025-9
**Character Count:** 13642
**Document Hash:** 6f88b97a5df32affd43dcb7618acb00e
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001729638-25-000006.hdr.sgml**: 20250930

**ACCESSION NUMBER**: 0001729638-25-000006

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

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20250930

**DATE AS OF CHANGE**: 20250930

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Transocean Ltd.
- **CENTRAL INDEX KEY:** 0001451505
- **STANDARD INDUSTRIAL CLASSIFICATION:** DRILLING OIL & GAS WELLS [1381]
- **ORGANIZATION NAME:** 01 Energy & Transportation
- **EIN:** 980599916
- **STATE OF INCORPORATION:** V8
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-84688
- **FILM NUMBER:** 251362282

**BUSINESS ADDRESS:**
- **STREET 1:** TURMSTRASSE 30
- **CITY:** STEINHAUSEN
- **STATE:** V8
- **ZIP:** 6312
- **BUSINESS PHONE:** 41 41 749 0500

**MAIL ADDRESS:**
- **STREET 1:** TURMSTRASSE 30
- **CITY:** STEINHAUSEN
- **STATE:** V8
- **ZIP:** 6312
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Mohn Frederik Wilhelm
- **CENTRAL INDEX KEY:** 0001729638

**ORGANIZATION NAME:**

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

**MAIL ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** TRANSOCEAN LTD, TURMSTRASSE 30
- **CITY:** STEINHAUSEN
- **PROVINCE COUNTRY:** V8

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

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**(Amendment No. 8)**

**TRANSOCEAN LTD.**

*(Name of Issuer)*

**Shares, $0.10 par value**

*(Title of Class of Securities)*

**H8817H100**

*(CUSIP Number)*

**c/o Daniel Ro-Trock**<br>Turmstrasse 30<br>Steinhausen V8 CH-6312<br>41 41 749 0500

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

**09/30/2025**

*(Date of Event Which Requires Filing of this Statement)*

| **CUSIP No.** | **H8817H100** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Frederik W. Mohn** | Name of reporting person<br>**Frederik W. Mohn** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**Q8** | Citizenship or place of organization<br>**Q8** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**343407.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**95074894.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**343407.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**95074894.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**95418301.00** | Aggregate amount beneficially owned by each reporting person<br>**95418301.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**10.1%** | Percent of class represented by amount in Row (11)<br>**10.1%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

**Comment for Reporting Person:** (1)	See Item 3 for additional information regarding the source of funds reported in Row (4).
(2)	The amounts reported in Row (7) and Row (9) include (a) 22,148 Shares individually owned by Mr. Mohn and (b) 321,259 Shares issuable in relation to vested restricted share units Mr. Mohn has the right to receive based upon his service as a director of the Issuer.
(3)	The amounts reported in Row (8), Row (10) and Row (11) include 95,074,894 Shares owned by Perestroika (Cyprus) Ltd.
(4)	The percentage reported in Row (13) is based upon the 943,124,986 Shares outstanding as of July 29, 2025, as disclosed by the Issuer in the Issuer's Quarterly Report on Form 10-Q filed with the U.S. Securities and Exchange Commission on August 5, 2025.

| **CUSIP No.** | **H8817H100** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Perestroika AS** | Name of reporting person<br>**Perestroika AS** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**Q8** | Citizenship or place of organization<br>**Q8** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**95074894.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**95074894.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**95074894.00** | Aggregate amount beneficially owned by each reporting person<br>**95074894.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**10.1%** | Percent of class represented by amount in Row (11)<br>**10.1%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**CO** | Type of Reporting Person (See Instructions)<br>**CO** | |

---

**Comment for Reporting Person:** (1)	See Item 3 for additional information regarding the source of funds reported in Row (4).
(2)	The amounts reported in Row (8), Row (10) and Row (11) include 95,074,894 Shares owned by Perestroika (Cyprus) Ltd.
(3)	The percentage reported in Row (13) is based upon the 943,124,986 Shares outstanding as of July 29, 2025, as disclosed by the Issuer in the Issuer's Quarterly Report on Form 10-Q filed with the U.S. Securities and Exchange Commission on August 5, 2025.

| **CUSIP No.** | **H8817H100** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Perestroika (Cyprus) Ltd** | Name of reporting person<br>**Perestroika (Cyprus) Ltd** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**G4** | Citizenship or place of organization<br>**G4** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**95074894.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**95074894.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**95074894.00** | Aggregate amount beneficially owned by each reporting person<br>**95074894.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**10.1%** | Percent of class represented by amount in Row (11)<br>**10.1%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**CO** | Type of Reporting Person (See Instructions)<br>**CO** | |

---

**Comment for Reporting Person:** (1)	See Item 3 for additional information regarding the source of funds reported in Row (4).
(2)	The percentage reported in Row (13) is based upon the 943,124,986 Shares outstanding as of July 29, 2025, as disclosed by the Issuer in the Issuer's Quarterly Report on Form 10-Q filed with the U.S. Securities and Exchange Commission on August 5, 2025.

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
Shares, $0.10 par value

**(b) Name of Issuer:**
TRANSOCEAN LTD.

**(c) Address of Issuer's Principal Executive Offices:**
Turmstrasse 30, Steinhausen, V8, CH-6312

This Amendment No. 8 to Schedule 13D (this "Amendment") amends the statement on Schedule 13D previously jointly filed by Frederik W. Mohn ("Mr. Mohn"), Perestroika AS, a Norwegian private limited company ("Perestroika AS"), Perestroika (Cyprus) Ltd., a Cyprus private limited company and a wholly owned subsidiary of Perestroika AS ("Perestroika Sub" and together with Perestroika AS, "Perestroika"), with the U.S. Securities and Exchange Commission on December 19, 2022, as previously amended (the "Prior Schedule 13D"). As used herein, "Reporting Persons" refers to Mr. Mohn, Perestroika AS and Perestroika Sub. Unless set forth in this Amendment, all Items are unchanged from the Prior Schedule 13D. Capitalized terms used and not defined herein shall have the meanings ascribed to them in the Prior Schedule 13D.

Item 1 is deleted in its entirety and replaced with the following:

This statement on Schedule 13D (as amended, this "Statement") relates to the shares, par value $0.10 per share (the "Shares"), of Transocean Ltd., a company organized under the laws of Switzerland (the "Issuer"). The Reporting Persons directly or indirectly hold Shares in the Issuer. The principal executive offices of the Issuer are located at Turmstrasse 30, CH-6312 Steinhausen, Switzerland.

**Item 5. Interest in Securities of the Issuer**

**(a)**
Item 5 is deleted in its entirety and replaced with the following:

The aggregate number and percentage of Shares (including Shares issued upon the Exchange Transaction) beneficially owned by the Reporting Persons are as follows (based upon the 943,124,986 Shares outstanding as of July 29, 2025, as disclosed by the Issuer in the Issuer's Quarterly Report on Form 10-Q filed with the U.S. Securities and Exchange Commission on August 5, 2025):

(i)	Mr. Mohn beneficially owns 95,418,301 Shares, or approximately 10.1%.

(ii)	Perestroika AS beneficially owns 95,074,894 Shares, or approximately 10.1%; and

(iii)	Perestroika Sub beneficially owns 95,074,894 Shares, or approximately 10.1%.

**(b)**
Mr. Mohn has:

(i)	sole power to vote or direct the vote of 343,407 Shares;

(ii)	shared power to vote or direct the vote of 95,074,894 Shares;

(iii)	sole power to dispose or direct the disposition of 343,407 Shares; and

(iv)	shared power to dispose or direct the disposition of 95,074,894 Shares.

Perestroika AS has:

(i)	sole power to vote or direct the vote of 0 Shares;

(ii)	shared power to vote or direct the vote of 95,074,894 Shares;

(iii)	sole power to dispose or direct the disposition of 0 Shares; and

(iv)	shared power to dispose or direct the disposition of 95,074,894 Shares.

Perestroika Sub has:

(i)	sole power to vote or direct the vote of 0 Shares;

(ii)	shared power to vote or direct the vote of 95,074,894 Shares;

(iii)	sole power to dispose or direct the disposition of 0 Shares; and

(iv)	shared power to dispose or direct the disposition of 95,074,894 Shares.

**(c)**
Except as described in Item 3 above, there have been no reportable transactions with respect to the Shares within the last 60 days by the Reporting Persons.

### 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.

**Reporting Person:** Frederik W. Mohn

**Signature:** /s/ Frederik W. Mohn

**Name/Title:** Frederik W. Mohn

**Date:** 09/30/2025

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.

**Reporting Person:** Perestroika AS

**Signature:** /s/ Frederik W. Mohn

**Name/Title:** Chairman and Sole Director

**Date:** 09/30/2025

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.

**Reporting Person:** Perestroika (Cyprus) Ltd

**Signature:** /s/ Frederik W. Mohn

**Name/Title:** Director

**Date:** 09/30/2025