# EDGAR Filing Document

**Accession Number:** 0001849820
**File Stem:** 0001193125-26-162090
**Filing Date:** 2026-4
**Character Count:** 22704
**Document Hash:** 405ed49391cee52d0635c917675c8033
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-162090.hdr.sgml**: 20260417

**ACCESSION NUMBER**: 0001193125-26-162090

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

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260417

**DATE AS OF CHANGE**: 20260417

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Nauticus Robotics, Inc.
- **CENTRAL INDEX KEY:** 0001849820
- **STANDARD INDUSTRIAL CLASSIFICATION:** GENERAL INDUSTRIAL MACHINERY & EQUIPMENT, NEC [3569]
- **ORGANIZATION NAME:** 06 Technology
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-92701
- **FILM NUMBER:** 26873086

**BUSINESS ADDRESS:**
- **STREET 1:** 17146 FEATHERCRAFT LANE
- **STREET 2:** SUITE 450
- **CITY:** WEBSTER
- **STATE:** TX
- **ZIP:** 77598
- **BUSINESS PHONE:** 281-942-9069

**MAIL ADDRESS:**
- **STREET 1:** 17146 FEATHERCRAFT LANE
- **STREET 2:** SUITE 450
- **CITY:** WEBSTER
- **STATE:** TX
- **ZIP:** 77598

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** cleantech Acquisition Corp.
- **DATE OF NAME CHANGE:** 20210308
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Material Impact Fund II, L.P.
- **CENTRAL INDEX KEY:** 0001804648

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

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

**BUSINESS ADDRESS:**
- **STREET 1:** 131 DARTMOUTH STREET
- **STREET 2:** FLOOR 3
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116
- **BUSINESS PHONE:** (617) 648-9100

**MAIL ADDRESS:**
- **STREET 1:** 131 DARTMOUTH STREET
- **STREET 2:** FLOOR 3
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116

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

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**(Amendment No. 6)**

**NAUTICUS ROBOTICS, INC.**

*(Name of Issuer)*

**Common Stock, $0.0001 par value per share**

*(Title of Class of Securities)*

**—**

*(CUSIP Number)*

**Shawna Sharkey**<br>c/o Material Impact<br>131 Dartmouth Street, Floor 3<br>Boston MA 02116<br>978-245-2248

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

**04/15/2026**

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

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Material Impact Partners II, LLC** | Name of reporting person<br>**Material Impact Partners II, LLC** | |
| 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>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 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>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| 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>**11719649.00** |
| 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>**11719649.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**11719649.00** | Aggregate amount beneficially owned by each reporting person<br>**11719649.00** | |
| 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>**25.2%** | Percent of class represented by amount in Row (11)<br>**25.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**OO** | Type of Reporting Person (See Instructions)<br>**OO** | |

---

**Comment for Reporting Person:** Consists of (i) 7,760 shares of Common Stock held of record by MIF II (as defined in Item 2(a) of the Original Schedule 13D), (ii) 11,800 shares of Common Stock issuable upon exercise of the Private Warrants (as defined in the Original Schedule 13D), (iii) 192,019 shares of Common Stock issuable upon conversion of the January 2024 Term Loans (as defined in the Original Schedule 13D) as of April 17, 2026, (iv) 1,342 shares of Common Stock issuable upon conversion of the September 2023 Term Loans (as defined in the Original Schedule 13D) as of April 17, 2026 (assuming conversion at the September 2023 Term Loan Conversion Price (as defined in the Original Schedule 13D)), (v) 11,479,623 shares of Common Stock underlying the Series A Preferred Stock (as defined in the Original Schedule 13D) (assuming a conversion at the conversion price of $0.5942 (the "Conversion Price")), and (vi) 27,105 shares of Common Stock underlying the dividends accrued for the Series A Preferred Stock. See Item 5(a) below for additional information regarding conversion of the September 2023 Term Loans and Series A Preferred Stock.  Excludes 1,541 Earn-Out Shares (as defined in the Original Schedule 13D) to be released upon the occurrence of a Triggering Event (as defined in the Original Schedule 13D). MIP II (as defined in Item 3 of the Original Schedule 13D) is the sole general partner of MIF II and may be deemed to have voting, investment and dispositive power with respect to these securities. Adam Sharkawy, a member of the Issuer's board of directors, and Carmichael Roberts are the managing members of MIP II and may be deemed to share voting, investment and dispositive power with respect to these securities.

Percentage based on 34,877,145 shares of Common Stock outstanding as of April 14, 2026, as reported by the Issuer in its Annual Report on Form 10-K, filed with the United States Securities and Exchange Commission (the Commission) on April 15, 2026 (the Form 10-K), plus (i) 11,800 shares of Common Stock issuable upon exercise of the Private Warrants, (ii) 192,019 shares of Common Stock issuable upon conversion of the January 2024 Term Loans as of April 17, 2026, (iii) 1,342 shares issuable upon the conversion of the September 2023 Term Loans as of April 17, 2026 (assuming conversion at the September 2023 Term Loan Conversion Price), (iv) 11,479,623 shares of Common Stock underlying the Series A Preferred Stock (assuming a conversion at the Conversion Price), and (v) 27,105 shares of Common Stock underlying the dividends accrued for the Series A Preferred Stock.

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Material Impact Fund II, L.P.** | Name of reporting person<br>**Material Impact Fund II, L.P.** | |
| 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>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 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>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| 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>**11719649.00** |
| 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>**11719649.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**11719649.00** | Aggregate amount beneficially owned by each reporting person<br>**11719649.00** | |
| 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>**25.2%** | Percent of class represented by amount in Row (11)<br>**25.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

**Comment for Reporting Person:** Consists of (i) 7,760 shares of Common Stock held of record by MIF II, (ii) 11,800 shares of Common Stock issuable upon exercise of the Private Warrants, (iii) 192,019 shares of Common Stock issuable upon conversion of the January 2024 Term Loans as of April 17, 2026, (iv) 1,342 shares of Common Stock issuable upon conversion of the September 2023 Term Loans as of April 17, 2026 (assuming conversion at the September 2023 Term Loan Conversion Price), (v) 11,479,623 shares of Common Stock underlying the Series A Preferred Stock (assuming a conversion at the Conversion Price), and (vi) 27,105 shares of Common Stock underlying the dividends accrued for the Series A Preferred Stock. See Item 5(a) below for additional information regarding conversion of the September 2023 Term Loans and Series A Preferred Stock.  Excludes 1,541 Earn-Out Shares to be released upon the occurrence of a Triggering Event. MIP II is the sole general partner of MIF II and may be deemed to have voting, investment and dispositive power with respect to these securities. Adam Sharkawy, a member of the Issuer's board of directors, and Carmichael Roberts are the managing members of MIP II and may be deemed to share voting, investment and dispositive power with respect to these securities.

Percentage based on 34,877,145 shares of Common Stock outstanding as of April 14, 2026, as reported by the Issuer in the Form 10-K, plus (i) 11,800 shares of Common Stock issuable upon exercise of the Private Warrants, (ii) 192,019 shares of Common Stock issuable upon conversion of the January 2024 Term Loans as of April 17, 2026, (iii) 1,342 shares issuable upon the conversion of the September 2023 Term Loans as of April 17, 2026 (assuming conversion at the September 2023 Term Loan Conversion Price), (iv) 11,479,623 shares of Common Stock underlying the Series A Preferred Stock (assuming a conversion at the Conversion Price), and (v) 27,105 shares of Common Stock underlying the dividends accrued for the Series A Preferred Stock.

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Adam Sharkawy** | Name of reporting person<br>**Adam Sharkawy** | |
| 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>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 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>**X1** | Citizenship or place of organization<br>**X1** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**3048.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**11719649.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**3048.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**11719649.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**11722697.00** | Aggregate amount beneficially owned by each reporting person<br>**11722697.00** | |
| 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>**25.2%** | Percent of class represented by amount in Row (11)<br>**25.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

**Comment for Reporting Person:** Shares of Common Stock reported in Items 7 and 9 are held by Adam Sharkawy individually.

Shares reported in Items 8 and 10 consist of (i) 7,760 shares of Common Stock held of record by MIF II, (ii) 11,800 shares of Common Stock issuable upon exercise of the Private Warrants, (iii) 192,019 shares of Common Stock issuable upon conversion of the January 2024 Term Loans as of April 17, 2026, (iv) 1,342 shares of Common Stock issuable upon conversion of the September 2023 Term Loans as of April 17, 2026 (assuming conversion at the September 2023 Term Loan Conversion Price), (v) 11,479,623 shares of Common Stock underlying the Series A Preferred Stock (assuming a conversion at the Conversion Price), and (vi) 27,105 shares of Common Stock underlying the dividends accrued for the Series A Preferred Stock. See Item 5(a) below for additional information regarding conversion of the September 2023 Term Loans and Series A Preferred Stock.  Excludes 1,541 Earn-Out Shares to be released upon the occurrence of a Triggering Event. MIP II is the sole general partner of MIF II and may be deemed to have voting, investment and dispositive power with respect to these securities. Adam Sharkawy, a member of the Issuer's board of directors, and Carmichael Roberts are the managing members of MIP II and may be deemed to share voting, investment and dispositive power with respect to these securities.

Percentage based on 34,877,145 shares of Common Stock outstanding as of April 14, 2026, as reported by the Issuer in the Form 10-K, plus (i) 11,800 shares of Common Stock issuable upon exercise of the Private Warrants, (ii) 192,019 shares of Common Stock issuable upon conversion of the January 2024 Term Loans as of April 17, 2026, (iii) 1,342 shares issuable upon the conversion of the September 2023 Term Loans as of April 17, 2026 (assuming conversion at the September 2023 Term Loan Conversion Price), (iv) 11,479,623 shares of Common Stock underlying the Series A Preferred Stock (assuming a conversion at the Conversion Price), and (v) 27,105 shares of Common Stock underlying the dividends accrued for the Series A Preferred Stock.

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Carmichael Roberts** | Name of reporting person<br>**Carmichael Roberts** | |
| 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>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 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>**X1** | Citizenship or place of organization<br>**X1** | |
| 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>**11719649.00** |
| 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>**11719649.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**11719649.00** | Aggregate amount beneficially owned by each reporting person<br>**11719649.00** | |
| 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>**25.2%** | Percent of class represented by amount in Row (11)<br>**25.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

**Comment for Reporting Person:** Consists of (i) 7,760 shares of Common Stock held of record by MIF II, (ii) 11,800 shares of Common Stock issuable upon exercise of the Private Warrants, (iii) 192,019 shares of Common Stock issuable upon conversion of the January 2024 Term Loans as of April 17, 2026, (iv) 1,342 shares of Common Stock issuable upon conversion of the September 2023 Term Loans as of April 17, 2026 (assuming conversion at the September 2023 Term Loan Conversion Price), (v) 11,479,623 shares of Common Stock underlying the Series A Preferred Stock (assuming a conversion at the Conversion Price), and (vi) 27,105 shares of Common Stock underlying the dividends accrued for the Series A Preferred Stock. See Item 5(a) below for additional information regarding conversion of the September 2023 Term Loans and Series A Preferred Stock.  Excludes 1,541 Earn-Out Shares to be released upon the occurrence of a Triggering Event. MIP II is the sole general partner of MIF II and may be deemed to have voting, investment and dispositive power with respect to these securities. Adam Sharkawy, a member of the Issuer's board of directors, and Carmichael Roberts are the managing members of MIP II and may be deemed to share voting, investment and dispositive power with respect to these securities.

Percentage based on 34,877,145 shares of Common Stock outstanding as of April 14, 2026, as reported by the Issuer in the Form 10-K, plus (i) 11,800 shares of Common Stock issuable upon exercise of the Private Warrants, (ii) 192,019 shares of Common Stock issuable upon conversion of the January 2024 Term Loans as of April 17, 2026, (iii) 1,342 shares issuable upon the conversion of the September 2023 Term Loans as of April 17, 2026 (assuming conversion at the September 2023 Term Loan Conversion Price), (iv) 11,479,623 shares of Common Stock underlying the Series A Preferred Stock (assuming a conversion at the Conversion Price), and (v) 27,105 shares of Common Stock underlying the dividends accrued for the Series A Preferred Stock.

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
Common Stock, $0.0001 par value per share

**(b) Name of Issuer:**
NAUTICUS ROBOTICS, INC.

**(c) Address of Issuer's Principal Executive Offices:**
17146 Feathercraft Lane, Suite 450, Webster, TX, 77598

Explanatory Note: This Amendment No. 6 (the Amendment) amends and supplements the Schedule 13D originally filed by the Reporting Persons with the Commission on September 19, 2022, as amended by Amendment No. 1 filed with the Commission on February 8, 2023, by Amendment No. 2 filed with the Commission on February 25, 2025, by Amendment No. 3 filed with the Commission on April 17, 2025, by Amendment No. 4 filed with the Commission on October 28, 2025 and by Amendment No. 5 filed with the Commission on December 16, 2025 (collectively, the Original Schedule 13D). This Amendment is being filed to reflect a material change in the aggregate percentage ownership reported by the Reporting Persons in the Original Schedule 13D solely due to an increase in the shares of Common Stock outstanding. The Reporting Persons have not purchased or sold any shares of Common Stock since the filing of Amendment No. 5.  Only those items that are hereby reported are amended; all other items reported in the Original Schedule 13D remain unchanged. Information given in response to each item shall be deemed incorporated by reference in all other items, as applicable. Capitalized terms not defined in this Amendment have the meanings ascribed to them in the Original Schedule 13D.

**Item 4. Purpose of Transaction**

The information set forth in Item 4 of the Original Schedule 13D is incorporated herein by reference.

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

**(a)**
See Items 7-11 of the cover pages of this Statement and Item 2 above.

**(b)**
See Items 7-11 of the cover pages of this Statement and Item 2 above.

**(c)**
Except as reported in this Statement, none of the Reporting Persons has effected any transactions in the Issuer's securities within the past 60 days.

**Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.**

The information set forth in Item 3 of this Statement is incorporated herein by reference.

### 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:** Material Impact Partners II, LLC

**Signature:** /s/ Carmichael Roberts

**Name/Title:** Carmichael Roberts, Managing Member of Material Impact Partners II, LLC, its General Partner

**Date:** 04/17/2026

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:** Material Impact Fund II, L.P.

**Signature:** /s/ Carmichael Roberts

**Name/Title:** Carmichael Roberts, Managing Member of Material Impact Partners II, LLC, its General Partner

**Date:** 04/17/2026

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:** Adam Sharkawy

**Signature:** /s/ Adam Sharkawy

**Name/Title:** Adam Sharkawy

**Date:** 04/17/2026

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:** Carmichael Roberts

**Signature:** /s/ Carmichael Roberts

**Name/Title:** Carmichael Roberts

**Date:** 04/17/2026