Exhibit 4.1


 


	NUMBER	UNITS
	U-	 


 


SEE REVERSE FOR CERTAIN DEFINITIONS


 


CUSIP 812204 204


 


SEAPORT CALIBRE MATERIALS ACQUISITION CORP.


 


UNITS CONSISTING
OF ONE SHARE OF CLASS A COMMON STOCK AND ONE-HALF OF ONE 

REDEEMABLE WARRANT,


 


EACH WHOLE WARRANT ENTITLING THE HOLDER TO
PURCHASE ONE SHARE OF CLASS A COMMON STOCK


 


THIS CERTIFIES THAT                     
is the owner of          Units.


 


Each Unit (“Unit”)
consists of one (1) share of Class A common stock, par value $0.0001 per share (“Common Stock”), of
Seaport Calibre Materials Acquisition Corp., a Delaware corporation (the “Company”), and one-half of one redeemable
warrant (the “Warrant”). Each whole Warrant entitles the holder to purchase one (1) share (subject
to adjustment) of Common Stock for $11.50 per share (subject to adjustment). Only whole Warrants are exercisable. Each whole Warrant
will become exercisable thirty (30) days after the Company’s completion of a merger, capital stock exchange, asset acquisition,
stock purchase, reorganization or other similar business combination with one or more businesses (each a “Business Combination”)
and will expire unless exercised before 5:00 p.m., New York City Time, on the date that is five (5) years after the date on which
the Company completes its initial Business Combination, or earlier upon redemption or liquidation (the “Expiration Date”). The
Common Stock and Warrants comprising the Units represented by this certificate are not transferable separately prior to           
, 2021, unless Seaport Global Securities LLC elects to allow separate trading earlier, subject to the Company’s filing of a Current
Report on Form 8-K with the Securities and Exchange Commission containing an audited balance sheet reflecting the Company’s
receipt of the gross proceeds of the Company’s initial public offering and filing a Current Report on Form 8-K and issuing a press
release announcing when separate trading will begin. No fractional Warrants will be issued upon separation of the Units. The terms
of the Warrants are governed by a Warrant Agreement, dated as of             
, 2021, between the Company and Continental Stock Transfer & Trust Company, as Warrant Agent, and are subject to the terms and
provisions contained therein, all of which terms and provisions the holder of this certificate consents to by acceptance hereof. Copies
of the Warrant Agreement are on file at the office of the Warrant Agent at 1 State Street, 30th Floor, New York, New York
10004, and are available to any Warrant holder on written request and without cost.


 


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


 


This certificate shall be
governed by and construed in accordance with the internal laws of the State of New York.


 


Witness the facsimile signature
of a duly authorized signatory of the Company.


 


	 	 	 	 	 
	Authorized Signatory	 	 	 	Transfer Agent


 









     


     


    

 


SEAPORT CALIBRE MATERIALS ACQUISITION CORP.


 


The Company will furnish
without charge to each unitholder who so requests, a statement of the powers, designations, preferences and relative, participating, optional
or other special rights of each class of stock or series thereof of the Company and the qualifications, limitations, or restrictions of
such preferences and/or rights.


 


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	 	 
	 	 	 	 	 	 	 	 	 	 	 
	TEN ENT       —     as tenants by the entireties	 	 	 	 	 	    (Cust)    	 	 	 	      (Minor)      
	 	 	 	 
	JT
    TEN           —     as joint tenants
    with right of survivorship and not as tenants in common	 	 	 	 	 	under Uniform Gifts to Minors Act
	 	 	 	 	 	 	 
	 	 	 	 	 	 	(State)


 


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


 


For value received,                     
hereby sell, assign and transfer unto                     


 


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


 


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


 


Units represented by the within Certificate,
and do hereby irrevocably constitute and appoint


 


Attorney to transfer the said Units
on the books of the within named Company with full power of substitution in the premises.


 


Dated 


	 	 
	 	 
	 	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:
	 
	 
	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 UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED (OR ANY SUCCESSOR RULE).


 


In each case, as
more fully described in, and subject to the terms and conditions described in, the Company’s final prospectus for its initial
public offering 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 its initial public offering only in the event that (i) the Company redeems the shares of
Class A common stock sold in the Company’s initial public offering and liquidates because it does not consummate an
initial business combination within the time period set forth in the Company’s amended and restated certificate of
incorporation, as the same may be amended from time to time (such date being referred to herein as the “Last Date”),
(ii) the Company redeems the shares of Class A common stock sold in its initial public offering in connection with a
stockholder vote to amend the Company’s amended and restated certificate of incorporation to modify the substance or timing of
the Company’s obligation to redeem 100% of the Class A common stock if it does not consummate an initial business
combination by the Last Date or with respect to any other
provision relating to stockholders’ rights or pre-initial business combination activity, or (iii) if the
holder(s) seek(s) to redeem for cash his, her or its respective shares of Class A common stock in connection with a
tender offer (or proxy solicitation, solely in the event the Company seeks stockholder 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.