Material Impact (NASDAQ: KITT) reports 25.2% stake in Nauticus

Rhea-AI Filing Summary

Material Impact Fund II and affiliates have amended their Schedule 13D to report a sizable stake in Nauticus Robotics, Inc. common stock. The group now beneficially owns 11,719,649 shares, representing 25.2% of Nauticus’s common stock, including both shares currently held and securities convertible into shares.

The position consists of common stock, private warrants, term loans that are convertible into common stock, Series A Preferred Stock convertible at a stated conversion price, and accrued dividend shares. One director, Adam Sharkawy, also holds 3,048 shares individually, bringing his total beneficial ownership to 11,722,697 shares, or 25.2% of the class. The filing notes that, aside from the transactions described, the reporting persons have not traded Nauticus securities in the past 60 days.

Insights

Equity ownership & governance analyst

Material Impact discloses a 25.2% economic and voting stake in Nauticus Robotics via equity and convertible instruments.

The reporting group, led by Material Impact Fund II and related entities, reports beneficial ownership of 11,719,649 Nauticus shares, or 25.2% of the common stock. This includes common shares, warrants, term loans convertible into equity, and Series A Preferred Stock plus accrued dividends.

The structure concentrates significant voting and dispositive power in a single sponsor group, with managing members Adam Sharkawy and Carmichael Roberts deemed to share control over these securities. The filing also confirms no additional transactions in Nauticus securities by the reporting persons during the 60 days prior to the reporting date.

Key Figures

Beneficial ownership: 11,719,649 shares Ownership percentage: 25.2% of common stock Shares outstanding: 34,877,145 shares +5 more

8 metrics

Beneficial ownership 11,719,649 shares Shares beneficially owned by Material Impact entities

Ownership percentage 25.2% of common stock Beneficial ownership percentage for each reporting person group

Shares outstanding 34,877,145 shares Nauticus common shares outstanding as of April 14, 2026

Series A Preferred underlying 11,479,623 shares Common shares underlying Series A Preferred Stock at $0.5942 Conversion Price

Convertible January 2024 Term Loans 192,019 shares Common shares issuable upon conversion as of April 17, 2026

Convertible September 2023 Term Loans 1,342 shares Common shares issuable upon conversion as of April 17, 2026

Accrued preferred dividends 27,105 shares Common shares underlying dividends accrued on Series A Preferred Stock

Sharkawy total beneficial stake 11,722,697 shares Includes 3,048 shares held individually plus shared Material Impact holdings

Key Terms

beneficially owned, Series A Preferred Stock, Conversion Price, Earn-Out Shares, +2 more

6 terms

beneficially owned financial

"11Aggregate amount beneficially owned by each reporting person 11,719,649.00"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

Series A Preferred Stock financial

"11,479,623 shares of Common Stock underlying the Series A Preferred Stock"

Series A preferred stock is a type of ownership share in a company that gives investors certain advantages, such as priority in receiving profits or getting their money back if the company is sold or goes bankrupt. It is often issued during early funding stages to attract investors by offering more security than common shares. This stock matters to investors because it provides a safer way to invest while still holding potential for future gains.

Conversion Price financial

"Series A Preferred Stock (assuming a conversion at the conversion price of $0.5942 (the "Conversion Price"))"

The conversion price is the fixed price at which a convertible security, like a bond or preferred stock, can be exchanged for shares of common stock. It acts like a set rate that determines how many shares an investor can receive if they choose to convert their investment. This helps investors understand the value and potential benefits of converting their securities into company shares.

Earn-Out Shares financial

"Excludes 1,541 Earn-Out Shares to be released upon the occurrence of a Triggering Event."

Earn-out shares are company shares promised to sellers or managers only if the business meets agreed future targets after a merger or acquisition, functioning like a performance-based payout instead of immediate cash. They matter to investors because they can dilute existing ownership, change future earnings prospects and reveal how confident buyers are about growth — like a conditional bonus that shifts payment and risk into the future.

Schedule 13D regulatory

"has previously filed a statement on Schedule 13G to report the acquisition"

A Schedule 13D is a legal document that investors file with regulators when they buy a large enough stake in a company to potentially influence its management or decisions. It provides details about the investor’s intention, ownership stake, and plans, helping other investors understand who is gaining control and what their motives might be.

dispositive power financial

"may be deemed to have voting, investment and dispositive power with respect to these securities."

Dispositive power is the authority to decide the final outcome of an asset, legal claim, contract, or corporate action — in effect the power to dispose of or resolve something. For investors it matters because whoever holds that authority can determine who gets paid, who controls an asset or vote, and how risks and returns are allocated; think of it like holding the key that lets you lock in the winner or loser in a deal.

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)

63911H306

(CUSIP Number)

Shawna Sharkey
c/o Material Impact, 131 Dartmouth Street, Floor 3
Boston, MA, 02116
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)

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.

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).

schemaVersion:

SCHEDULE 13D

CUSIP Number(s): 63911H306

1

Name of reporting person

Material Impact Partners II, LLC

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)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 11,719,649.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 11,719,649.00

11

Aggregate amount beneficially owned by each reporting person

11,719,649.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

25.2 %

14

Type of Reporting Person (See Instructions)

OO

Comment for Type of 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.

SCHEDULE 13D

CUSIP Number(s): 63911H306

1

Name of reporting person

Material Impact Fund II, L.P.

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)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 11,719,649.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 11,719,649.00

11

Aggregate amount beneficially owned by each reporting person

11,719,649.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

25.2 %

14

Type of Reporting Person (See Instructions)

PN

Comment for Type of 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.

SCHEDULE 13D

CUSIP Number(s): 63911H306

1

Name of reporting person

Adam Sharkawy

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)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 3,048.00
8	Shared Voting Power 11,719,649.00
9	Sole Dispositive Power 3,048.00
10	Shared Dispositive Power 11,719,649.00

11

Aggregate amount beneficially owned by each reporting person

11,722,697.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

25.2 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of 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.

SCHEDULE 13D

CUSIP Number(s): 63911H306

1

Name of reporting person

Carmichael Roberts

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)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 11,719,649.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 11,719,649.00

11

Aggregate amount beneficially owned by each reporting person

11,719,649.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

25.2 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of 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.

SCHEDULE 13D

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, TEXAS , 77598.
Item 1 Comment: 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 2.	Identity and Background
(a)	The information set forth in Item 2(a) of the Original Schedule 13D is incorporated herein by reference.
(b)	The information set forth in Item 2(b) of the Original Schedule 13D is incorporated herein by reference.
(c)	The information set forth in Item 2(c) of the Original Schedule 13D is incorporated herein by reference.
(d)	The information set forth in Item 2(d) of the Original Schedule 13D is incorporated herein by reference.
(e)	The information set forth in Item 2(e) of the Original Schedule 13D is incorporated herein by reference.
(f)	The information set forth in Item 2(f) of the Original Schedule 13D is incorporated herein by reference.
Item 3.	Source and Amount of Funds or Other Consideration
	The information set forth in Item 3 of the Original Schedule 13D is incorporated herein by reference.
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.
(d)	Under certain circumstances set forth in the limited partnership agreement of MIF II, the general partner and limited partners of MIF II may be deemed to have the right to receive dividends from, or the proceeds from, the sale of shares of the Issuer owned by MIF II.
(e)	Not applicable
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.

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

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

Adam Sharkawy

Signature:	/s/ Adam Sharkawy
Name/Title:	Adam Sharkawy
Date:	04/17/2026

Carmichael Roberts

Signature:	/s/ Carmichael Roberts
Name/Title:	Carmichael Roberts
Date:	04/17/2026

FAQ

How much of Nauticus Robotics (KITT) does Material Impact now beneficially own?

Material Impact Fund II and related reporting persons beneficially own 11,719,649 shares of Nauticus Robotics common stock, representing 25.2% of the class. This figure includes both currently outstanding shares and various securities that are convertible into common stock.

What securities make up Material Impact’s 25.2% stake in Nauticus Robotics (KITT)?

The 25.2% stake includes common stock, private warrants, convertible January 2024 and September 2023 term loans, Series A Preferred Stock at a set conversion price, and accrued dividend shares tied to that preferred stock, all counted on an as-converted basis.

What is the share count Nauticus Robotics (KITT) used to calculate Material Impact’s ownership percentage?

The ownership percentage is based on 34,877,145 common shares outstanding as of April 14, 2026, plus additional shares issuable from warrants, convertible term loans, Series A Preferred Stock, and accrued dividends, as described in Nauticus’s most recent annual report.

How many Nauticus Robotics (KITT) shares does Adam Sharkawy personally and indirectly control?

Adam Sharkawy reports beneficial ownership of 11,722,697 shares, or 25.2% of Nauticus common stock. This includes 3,048 shares held individually and the larger stake held through Material Impact entities over which he shares voting and investment authority.

Has Material Impact traded Nauticus Robotics (KITT) shares recently according to this Schedule 13D/A?

According to the filing, none of the reporting persons effected transactions in Nauticus Robotics securities within the 60 days before the reported event date, other than the positions and instruments specifically described in the ownership breakdown.