8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) ofthe Securities Exchange Act of 1934

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Date of Report (Date of earliest event reported): March 13, 2026

Eureka Acquisition Corp
(Exact name of registrant as specified in its charter)
Cayman Islands	001-42152	N/A
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(State or other jurisdiction	(Commission File Number)	(IRS Employer
of incorporation)		Identification Number)

14 Prudential Tower

Singapore 049712

(Address of principal executive offices)

(+1) 949 899 1827

**(**Registrant’s telephone number, including area code)

Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☒	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
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☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
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☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))
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Securities registered pursuant to Section 12(b) of the Act.

Title of each class	Trading Symbol	Name of each exchange on which registered
Units, consisting of one Class A ordinary share, $0.0001 par value, and one Right to acquire one-fifth of one Class A ordinary share	EURKU	The Nasdaq Stock Market LLC
Class A ordinary shares, par value $0.0001 per share	EURK	The Nasdaq Stock Market LLC
Rights, each whole right to acquire one-fifth of one Class A ordinary share	EURKR	The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.01. Entry into a Material Definitive Agreement

The disclosures set forth under Item 2.03 are incorporated by reference.

Item 2.03 Creation of a Direct Financial Obligationor an Obligation under an Off-Balance Sheet Arrangement of a Registrant

Pursuant to the amended and restated memorandum and articles of association (the “Charter”) of Eureka Acquisition Corp, a Cayman Islands exempted company (the “Company”), the Company had until March 3, 2026 to complete its initial business combination, however the Company may extend the period of time to consummate a business combination up to July 3, 2026, each by a one-month extension, subject to the deposit of $150,000 (the “Monthly Extension Fee”) into the trust account of the Company (the “TrustAccount”).

On or around March 3, 2026, an aggregate of $150,000 of the Monthly Extension Fee was deposited into the Trust Account for the public shareholders, which enables the Company to extend the period of time it has to consummate its initial business combination by one month from March 3, 2026 to April 3, 2026 (the “Extension”). The payment of the Monthly Extension Fee was made by Marine Thinking Inc. (“MarineThinking”), pursuant to that certain business combination agreement dated as of October 29, 2025 (as the same may be amended, supplemented or otherwise modified from time to time, the “BCA”), with Marine Thinking, an autonomous ship and fleet solution providing company incorporated under the Canada Business Corporations Act (“CBCA”), and 17358750 Canada Inc., a company incorporated under the CBCA and a wholly-owned subsidiary of Eureka (the “Amalgamation Sub”).

The Company issued an unsecured promissory note in the aggregate principal amount of $150,000 (the “Extension Note”) dated March 13, 2026 to Marine Thinking in connection with the payment of the Monthly Extension Fee.

The Extension Note bears no interest and is payable in full upon the earlier to occur of (i) the consummation of the Company’s business combination or (ii) the date of expiry of the term of the Company (the “Maturity Date”). The following shall constitute an event of default: (i) a failure to pay the principal within five business days of the Maturity Date; (ii) the commencement of a voluntary or involuntary bankruptcy action, (iii) the breach of the Company’s obligations thereunder; (iv) any cross defaults; (v) an enforcement proceedings against the Company; and (vi) any unlawfulness and invalidity in connection with the performance of the obligations thereunder, in which case the Extension Note may be accelerated.

The payee of the Extension Note, Marine Thinking or its registered assignees or successors in interest, has the right, but not the obligation, to convert the Extension Note, in whole or in part, respectively, into private units (the “Units”) of the Company, each consisting of one Class A ordinary share, par value $0.0001 per share (the “Class A Ordinary Share”) and one right to receive one-fifth (1/5) of one Class A Ordinary Share upon the consummation of a business combination, as described in the prospectus of the Company (File No: 333-277780), by providing the Company with written notice of the intention to convert at least two business days prior to the closing of the business combination. The number of Units to be received by Marine Thinking in connection with such conversion shall be an amount determined by dividing (x) the sum of the outstanding principal amount payable to Marine Thinking by (y) $10.00.

The issuance of the Extension Note was made pursuant to the exemption from registration contained in Section 4(a)(2) of the Securities Act of 1933, as amended.

A copy of the Extension Note is attached as Exhibit 10.1 to this Current Report on Form 8-K and is incorporated herein by reference. The foregoing description of the Extension Note does not purport to be complete and is subject to, and is qualified in its entirety by, the full text of the Extension Note.

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Item 3.02 Unregistered Sales of Equity Securities

The information disclosed under Item 2.03 of this Current Report on Form 8-K is incorporated by reference into this Item 3.02 to the extent required herein. The Units (and the underlying securities) issuable upon conversion of the Note, if any, (1) may not, subject to certain limited exceptions, be transferable or salable by Marine Thinking until the completion of the Company’s initial business combination and (2) are entitled to registration rights.

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Additional Information and Where to Find It

In connection with the proposed transaction, the Company intends to file with the SEC a registration statement on Form S-4 that will include a proxy statement for the shareholders of the Company that also constitutes a prospectus of the Company. The Company urges investors, shareholders and other interested persons to read, when available, the preliminary proxy statement/prospectus as well as other documents filed with the SEC because these documents will contain important information about the Company, Marine Thinking, Amalgamation Sub and the proposed transactions. After the registration statement is declared effective, the definitive proxy statement/prospectus to be included in the registration statement will be mailed to shareholders of the Company as of a record date to be established for voting on the proposed transactions. Shareholders will also be able to obtain a copy of the proxy statement/prospectus, without charge by directing a request to eric.zhang@herculescapital.group. The preliminary and definitive proxy statement/prospectus to be included in the registration statement, once available, can also be obtained, without charge, at the SEC’s website (www.sec.gov).

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No Offer or Solicitation

This Current Report on Form 8-K is not a proxy statement or solicitation of a proxy, consent or authorization with respect to any securities or in respect of the proposed transactions described herein, and does not constitute an offer to sell or a solicitation of an offer to buy any securities of the Company or the Marine Thinking, or a solicitation of any vote or approval, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offer of securities shall be made except by means of a prospectus meeting the requirements of the Securities Act of 1933, as amended.

Participants in the Solicitation

The Company, Marine Thinking and their respective directors and executive officers may be considered participants in the solicitation of proxies with respect to the proposed transactions under the rules of the SEC. Information about the directors and executive officers of the Company is set forth in the Company’s most recent Annual Report on Form 10-K, which was filed with the SEC on December 15, 2025. Information regarding the persons who may, under the rules of the SEC, be deemed participants in the solicitation of the stockholders in connection with the proposed transactions will be set forth in the proxy statement/prospectus when it is filed with the SEC. These documents can be obtained free of charge from the sources indicated above.

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Forward-Looking Statements

Certain statements contained in this Current Report on Form 8-K may be considered forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995, Section 27A of the Securities Act and Section 21E of the Exchange Act, including statements regarding the proposed transaction involving the Company and Marine Thinking, and the ability to consummate the proposed transaction. Forward-looking statements generally include statements that are predictive in nature and depend upon or refer to future events or conditions, and include words such as “may,” “will,” “should,” “would,” “expect,” “anticipate,” “plan,” “likely”, “believe,” “estimate,” “project,” “intend,” and other similar expressions among others. Statements that are not historical facts are forward-looking statements. Forward-looking statements are based on current beliefs and assumptions that are subject to risks and uncertainties and are not guarantees of future performance. Actual results could differ materially from those contained in any forward-looking statement as a result of various factors, including, without limitation: (i) the risk that the conditions to the closing of the proposed transaction are not satisfied, including the failure to timely or at all obtain shareholder approval for the proposed transaction or the failure to timely or at all obtain any required regulatory approval; (ii) uncertainties as to the timing of the consummation of the proposed transaction and the ability of each of involving the Company and Marine Thinking to consummate the proposed transaction; (iii) the possibility that other anticipated benefits of the proposed transaction will not be realized, and the anticipated tax treatment of the proposed transaction; (iv) the occurrence of any event that could give rise to termination of the proposed transaction; (v) the risk that shareholder litigation in connection with the proposed transaction or other settlements or investigations may affect the timing or occurrence of the proposed transaction or result in significant costs of defense, indemnification and liability; (vi) changes in general economic and/or industry specific conditions; (vii) possible disruptions from the proposed transaction that could harm the Company business; (viii) the ability of the Company to retain, attract and hire key personnel; (ix) potential adverse reactions or changes to relationships with customers, employees, suppliers or other parties resulting from the announcement or completion of the proposed transaction; (x) potential business uncertainty, including changes to existing business relationships, during the pendency of the proposed transaction that could affect the Company’s financial performance; (xi) legislative, regulatory and economic developments; (xii) unpredictability and severity of catastrophic events, including, but not limited to, acts of terrorism, outbreak of war or hostilities and any epidemic, pandemic or disease outbreak, as well as management’s response to any of the aforementioned factors; and (xiii) other risk factors as detailed from time to time in the Company’s reports filed with the SEC, including the Company’s annual report on Form 10-K, periodic quarterly reports on Form 10-Q, periodic current reports on Form 8-K and other documents filed with the SEC. The foregoing list of important factors is not exclusive. Neither the Company nor Marine Thinking can give any assurance that the conditions to the proposed transaction will be satisfied. Except as required by applicable law, neither the Company nor Marine Thinking undertakes any obligation to revise or update any forward-looking statement, or to make any other forward-looking statements, whether as a result of new information, future events or otherwise.

Item 9.01 Financial Statements and Exhibits

Exhibit No.	Description of Exhibits
10.1	Extension Promissory Note dated March 13, 2025, issued by the Company to Marine Thinking Inc.
104	Cover Page Interactive Data File (embedded within the Inline XBRL document)

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	Eureka Acquisition Corp
	By:	/s/ Fen Zhang
	Name:	Fen Zhang
	Title:	Chief Executive Officer
Date: March 16, 2026

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Exhibit 10.1

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THIS PROMISSORY NOTE (“NOTE”) HASNOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”). THIS NOTE HAS BEEN ACQUIRED FOR INVESTMENTONLY AND MAY NOT BE SOLD, TRANSFERRED OR ASSIGNED IN THE ABSENCE OF REGISTRATION OF THE RESALE THEREOF UNDER THE SECURITIES ACT OR ANOPINION OF COUNSEL REASONABLY SATISFACTORY IN FORM, SCOPE AND SUBSTANCE TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED.

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PROMISSORY NOTE

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Principal Amount: US$150,000.00

Dated: March 13, 2026

New York, New York

FOR VALUE RECEIVED, Eureka Acquisition Corp (the “Maker” or the “Company”) promises to pay to the order of Marine Thinking Inc., or its registered assignees or successors in interest (the “Payee”), the principal sum of USD ONE HUNDRED AND FIFTY THOUSAND ONLY (US$150,000.00), on the terms and conditions described below. All payments on this Note shall be made by wire transfer of immediately available funds to such account as the Payee may from time to time designate by written notice in accordance with the provisions of this note (the “Note”).

1.	Principal. The principal balance of this Note shall be payable by the Maker to the Payee upon the<br>date on which the Maker consummates a business combination or merger with a qualified target company (as described in its Prospectus (as<br>defined below)) (a “Business Combination”) or the date of expiry of the term of the Maker, whichever is earlier (such<br>date, the “Maturity Date”). The principal balance may be prepaid at any time prior to the Maturity Date without penalty.<br>Under no circumstances shall any individual, including but not limited to any officer, director, employee or stockholder of the Maker,<br>be obligated personally for any obligations or liabilities of the Maker hereunder.
2.	Conversion Rights. The Payee has the right, but not the obligation, to convert this Note, in whole<br>or in part, into private unit (the “Units”) of the Maker, each consisting of one Class A ordinary share and one right<br>to receive one-fifth (1/5) of one Class A ordinary share upon the consummation of a Business Combination, as described in the Prospectus<br>of the Maker (File No. 333-277780) (the “Prospectus”), by providing the Maker with written notice of its intention<br>to convert this Note at least two business days prior to the closing of a Business Combination. The number of Units to be received by<br>the Payee in connection with such conversion shall be an amount determined by dividing (x) the sum of the outstanding principal amount<br>payable to such Payee by (y) $10.00.
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(a)	Fractional Units. No fractional Units will be issued upon conversion of this Note. In lieu of any<br>fractional Units to which Payee would otherwise be entitled, the Maker will pay to Payee in cash the amount of the unconverted principal<br>balance of this Note that would otherwise be converted into such fractional Units.
(b)	Effect of Conversion. If the Maker timely receives notice of the Payee’s intention to convert<br>this Note at least two business days prior to the closing of a Business Combination, this Note shall be deemed to be converted on such<br>closing date. At its expense, the Maker will, upon receipt of such conversion notice, as soon as practicable after consummation of a Business<br>Combination, issue and deliver to Payee, at Payee’s address as requested by Payee in its conversion notice, a certificate or certificates<br>for the number of Units to which Payee is entitled upon such conversion (bearing such legends as are customary pursuant to applicable<br>state and federal securities laws), including a check payable to Payee for any cash amounts payable as a result of any fractional Units<br>as described herein.
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3.	Interest. This Note does not carry any interest on the unpaid principal balance of this Note, provided,<br>that, any overdue amounts shall accrue default interest at a rate per annum equal to the interest rate which is the prevailing short term<br>United States Treasury Bill rate, from the date on which such payment is due until the day on which all sums due are received by the Payee.
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4.	Application of Payments. All payments shall be applied first to payment in full of any costs incurred<br>in the collection of any sum due under this Note, including but not limited to reasonable attorney’s and auditor’s fees and<br>expenses, then to the payment in full of any late charges, and finally to the reduction of the unpaid principal balance of this Note.
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5.	Events of Default. The following shall constitute an event of default (each, an “Eventof Default”):
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(a)	Failure to Make Required Payments. Failure by the Maker to pay the principal amount due pursuant<br>to this Note more than ten business days of the Maturity Date.
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(b)	Voluntary Bankruptcy, etc. The commencement by the Maker of a voluntary case under any applicable<br>bankruptcy, insolvency, reorganization, rehabilitation or other similar law, or the consent by it to the appointment of or taking possession<br>by a receiver, liquidator, assignee, trustee, custodian, sequestrator (or other similar official) of the Maker or for any substantial<br>part of its property, or the making by it of any assignment for the benefit of creditors, or the failure of the Maker generally to pay<br>its debts as such debts become due, or the taking of corporate action by the Maker in furtherance of any of the foregoing.
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(c)	Involuntary Bankruptcy, etc. The entry of a decree or order for relief by a court having jurisdiction<br>in the premises in respect of the Maker in an involuntary case under any applicable bankruptcy, insolvency or other similar law, or appointing<br>a receiver, liquidator, assignee, custodian, trustee, sequestrator (or similar official) of the Maker or for any substantial part of its<br>property, or ordering the winding-up or liquidation of its affairs, and the continuance of any such decree or order unstayed and in effect<br>for a period of 60 consecutive days.
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(d)	Breach of Other Obligations. The Maker fails to perform or comply with any one or more of its obligations<br>under this Note.
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(e)	Cross Default. Any present or future indebtedness of the Maker in respect of moneys borrowed<br>or raised becomes (or becomes capable of being declared) due and payable prior to its stated maturity by reason of any event of default,<br>or any such indebtedness is not paid when due or, as the case may be, within any applicable grace period.
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(f)	Enforcement Proceedings. A distress, attachment, execution or other legal process is levied or<br>enforced on or against any assets of the Maker which is not discharged or stayed within 30 days.
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(g)	Unlawfulness and Invalidity. It is or becomes unlawful for the Maker to perform any of its obligations<br>under this Note, or any obligations of the Maker under this Note are not or cease to be legal, valid, binding or enforceable.
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6.	Remedies.
(a)	Upon the occurrence of an Event of Default specified in Section 5(a) and 5(d) hereof, the Payee may, by<br>written notice to the Maker, declare this Note to be due immediately and payable, whereupon the unpaid principal amount of this Note,<br>and all other amounts payable hereunder, shall become immediately due and payable without presentment, demand, protest or other notice<br>of any kind, all of which are hereby expressly waived, notwithstanding anything contained herein or in the documents evidencing the same<br>to the contrary.
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(b)	Upon the occurrence of an Event of Default specified in Sections 5(b), 5(c), 5(e), 5(f) and 5(g) hereof,<br>the unpaid principal balance of this Note, and all other sums payable with regard to this Note hereunder, shall automatically and immediately<br>become due and payable, in all cases without any action on the part of the Payee.
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7.	Taxes. The Maker will pay all amounts due hereunder free and clear of and without reduction for<br>any taxes, levies, imposts, deductions, withholding or charges imposed or levied by any governmental authority or any political subdivision<br>or taxing authority thereof with respect thereto (“Taxes”). The Maker will pay on behalf of the Payee all such Taxes<br>so imposed or levied and any additional amounts as may be necessary so that the net payment of principal and any interest on this Note<br>received by the Payee after payment of all such Taxes shall be not less than the full amount provided hereunder.
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8.	Waivers. The Maker and all endorsers and guarantors of, and sureties for, this Note waive presentment<br>for payment, demand, notice of dishonor, protest, and notice of protest with regard to the Note, all errors, defects and imperfections<br>in any proceedings instituted by the Payee under the terms of this Note, and all benefits that might accrue to the Maker by virtue of<br>any present or future laws exempting any property, real or personal, or any part of the proceeds arising from any sale of any such property,<br>from attachment, levy or sale under execution, or providing for any stay of execution, exemption from civil process, or extension of time<br>for payment; and the Maker agrees that any real estate that may be levied upon pursuant to a judgment obtained by virtue hereof or any<br>writ of execution issued hereon, may be sold upon any such writ in whole or in part in any order desired by the Payee.
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9.	Unconditional Liability. The Maker hereby waives all notices in connection with the delivery, acceptance,<br>performance, default, or enforcement of the payment of this Note, and agrees that its liability shall be unconditional, without regard<br>to the liability of any other party, and shall not be affected in any manner by any indulgence, extension of time, renewal, waiver or<br>modification granted or consented to by the Payee, and consents to any and all extensions of time, renewals, waivers, or modifications<br>that may be granted by the Payee with respect to the payment or other provisions of this Note, and agrees that additional makers, endorsers,<br>guarantors, or sureties may become parties hereto without notice to the Maker or affecting the Maker’s liability hereunder. For<br>the purpose of this Note, “business day” shall mean a day (other than a Saturday, Sunday or public holiday) on which banks<br>are open in China and New York for general banking business.
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10.	Notices. All notices, statements or other documents which are required or contemplated by this<br>Note shall be made in writing and delivered: (i) personally or sent by first class registered or certified mail, overnight courier service<br>to the address most recently provided in writing to such party or such other address as may be designated in writing by such party, (ii)<br>by fax to the number most recently provided to such party or such other fax number as may be designated in writing by such party, or (iii)<br>by email, to the email address most recently provided to such party or such other email address as may be designated in writing by such<br>party. Any notice or other communication so transmitted shall be deemed to have been given on (a) the day of delivery, if delivered personally,<br>(b) only if the receipt is acknowledged, the day after such receipt, if sent by fax or email, (c) the business day after delivery to an<br>overnight courier service, if sent by an overnight courier service, or (d) 5 days after mailing if sent by first class registered or certified<br>mail.
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11.	Construction. This Note shall be construed and enforced in accordance with the laws of New York,<br>without regard to conflict of law provisions thereof.
12.	Severability. Any provision contained in this Note which is prohibited or unenforceable in any<br>jurisdiction shall, as to such jurisdiction, be ineffective to the extent of such prohibition or unenforceability without invalidating<br>the remaining provisions hereof, and any such prohibition or unenforceability in any jurisdiction shall not invalidate or render unenforceable<br>such provision in any other jurisdiction. The Payee hereby waives any and all right, title, interest or claim of any kind (“Claim”)<br>in or to any amounts contained in the trust account deriving from the proceeds of the IPO conducted by the Maker and the proceeds of the<br>sale of securities in a private placement (if any) prior to the effectiveness of the IPO, as described in greater detail in the Prospectus<br>filed with the Securities and Exchange Commission in connection with the IPO (the “Trust Account Funds”), and hereby<br>agrees not to seek recourse, reimbursement, payment or satisfaction for any Claim from the Trust Account Funds or any distribution therefrom<br>for any reason whatsoever. If Maker does not consummate the Business Combination, this Note shall be repaid only from amounts other than<br>Trust Account Funds, if any.
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13.	Amendment; Waiver. Any amendment hereto or waiver of any provision hereof may be made with, and<br>only with, the written consent of the Maker and the Payee.
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14.	Assignment. This Note shall be binding upon the Maker and its successors and assigns and is for<br>the benefit of the Payee and its successors and assigns, except that the Maker may not assign or otherwise transfer its rights or obligations<br>under this Note. The Payee may at any time without the consent of or notice to the Maker assign to one or more entities all or a portion<br>of its rights under this Note.
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[signature page follows]

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The Parties, intending to be legally bound hereby, have caused this Note to be duly executed by the undersigned as of the day and year first above written.

MAKER:

Eureka Acquisition Corp

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By:	/s/ Fen Zhang
Name:	Fen Zhang
Title:	CEO and Director

PAYEE:

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Marine Thinking Inc.

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By:	/s/ Sebastien Pare
Name:	Sebastien Pare
Title:	CEO

[signature page to the promissory note]