S.C. Code Ann. § 50-23-345: Temporary certificate of number.

(A) A transferee shall utilize the temporary certificate of number on the department's application form as a temporary certificate of number to permit the use of watercraft while applications for certificates of number are processed. Temporary certificates of number apply to new and previously owned watercraft. A temporary certificate is valid for not more than sixty days from the date of purchase. No temporary certificate of number may be issued for a boat, boat motor, or watercraft until the ad valorem tax is paid for the year for which the registration is to be issued.

(B) When using a recently purchased watercraft under authority of a temporary certificate of number, the operator shall carry a copy of the bill of sale on board along with the temporary certificate of number.

(C) A temporary certificate of number must not be issued for a watercraft not having a hull or manufacturer's identification number.

(D) Duplicate or updated temporary certificates of number or updated bills of sale are prohibited.

(E) The number assigned to a temporary certificate of number must not be displayed on the watercraft.

(F) A transferee may operate a newly acquired outboard motor for sixty days while application for title is pending provided the bill of sale is in possession while operating the motor.