Exhibit 4.2

   

  SPECIMEN CLASS A ORDINARY SHARE CERTIFICATE

   

  	NUMBER	SHARES


   

  BLUE OCEAN ACQUISITION CORP

  INCORPORATED UNDER THE LAWS OF THE CAYMAN ISLANDS

  CLASS A ORDINARY SHARES

   

  SEE REVERSE FOR

      CERTAIN DEFINITIONS

   

  CUSIP [ ]

   

  This Certifies that                     is the owner of                     

   

  FULLY PAID AND NON-ASSESSABLE CLASS A ORDINARY SHARES OF THE PAR VALUE OF US$0.0001 EACH
        OF

  BLUE OCEAN ACQUISITION CORP (THE “COMPANY”)

   

  subject to the Company’s amended and restated memorandum and articles of association, as
        the same may be amended from time to time, and transferable on the books of the Company in person or by duly authorized attorney upon surrender of this certificate properly endorsed.

   

  The Company will be forced to redeem all of its Class A ordinary shares if it is unable to
        complete a business combination within the period set forth in the Company’s amended and restated memorandum and articles of association, as the same may be amended from time to time, all as more fully described in the Company’s final prospectus
        dated           , 2021.

   

  This certificate is not valid unless countersigned by the Transfer Agent and registered by
        the Registrar.

   

  Witness the facsimile signatures of its duly authorized officers.

   

  Date: _________________

   

  	Chairman	 	Chief Executive Officer
	 	 	 
	 	Cayman Islands	 
	 	 	 


   

  

  	Chief Financial Officer	 
	 	 
	 	 


  

  

  

  
     

    
      
 

  

  BLUE OCEAN ACQUISITION CORP

   

  The Company will furnish without charge to each shareholder who so requests the powers,
      designations, preferences and relative, participating, optional or other special rights of each class of shares or series thereof of the Company and the qualifications, limitations, or restrictions of such preferences and/or rights. This certificate
      and the shares represented thereby are issued and shall be held subject to all the provisions of the Company’s amended and restated memorandum and articles of association, as the same may be amended from time to time, and resolutions of the Board of
      Directors providing for the issue of Class A ordinary shares (copies of which may be obtained from the secretary of the Company), to all of which the holder of this certificate by acceptance hereof assents. The following abbreviations, when used in
      the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable laws or regulations:

   

  	TEN COM	—	as tenants in common	 	UNIF GIFT MIN ACT	—	 	Custodian	 
	 	 	 	 	 	 	(Cust)	 	(Minor)
	 	 	 	 	 	 	 
	TEN ENT	—	as tenants by the entireties	 	 	 	under Uniform Gifts to Minors Act
	 	 	 	 	 	 	 
	 	 	 	 	 	 	(State)
	JT TEN	—	
          as joint tenants with right of

          survivorship and not as tenants in

          common 

        	 	 	 	 


   

  Additional abbreviations may also be used though not in the above list.

   

  For value received, ___________________________________________hereby sells, assigns and transfers unto

    

  

  

   

  
  

  (PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER(S) OF ASSIGNEE(S))

   

    

  

   (PLEASE
      PRINT OR TYPEWRITE NAME(S) AND ADDRESS(ES), INCLUDING ZIP CODE, OF ASSIGNEE(S)) 

   

  ____________________Shares represented by the within Certificate, and does hereby
      irrevocably constitute and appoint___________________________________________ Attorney to transfer the said shares on the books of the within named Company with full power of substitution in the premises.

   

  	Dated:	 	 	 
	 	 	 	Shareholder
	 	 	 	NOTICE: THE SIGNATURE(S) TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS
            WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATEVER.


   

  	Signature(s) Guaranteed:	 
	 	 
	By	 
	 	 
	 	 


  THE SIGNATURE(S) MUST BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN
      ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM, PURSUANT TO S.E.C. RULE 17Ad-15 OR ANY SUCCESSOR RULE).

   

  In each case, as more fully described in the Company’s final prospectus dated           ,
      2021, the holder(s) of this certificate shall be entitled to receive a pro-rata portion of certain funds held in the trust account established in connection with the Company’s initial public offering only in the event that (i) the Company redeems the
      Class A ordinary shares sold in its initial public offering and liquidates because it does not consummate an initial business combination within the period of time set forth in the Company’s amended and restated memorandum and articles of
      association, as the same may be amended from time to time, (ii) the Company redeems the Class A ordinary shares sold in its initial public offering in connection with a shareholder vote to amend the Company’s amended and restated memorandum and
      articles of association that would affect the substance or timing of the Company’s obligation to provide for the redemption of Class A ordinary shares in connection with an initial business combination or to redeem 100% of the Class A ordinary shares
      if it does not consummate an initial business combination within the time period set forth therein, or (iii) if the holder(s) seek(s) to redeem for cash his, her or its respective Class A ordinary shares in connection with a tender offer (or proxy
      solicitation, solely in the event the Company seeks shareholder approval of the proposed initial business combination) setting forth the details of a proposed initial business combination. In no other circumstances shall the holder(s) have any right
      or interest of any kind in or to the trust account.