California Code, Vehicle Code - VEH § 9862

(a) If the initial application for a number is not received by the department on or before the date set by the department, a penalty of one-half of the fee shall be assessed. If a certificate of number is not renewed on or before midnight of the expiration date, a penalty of one-half of the fee shall be assessed.

(b) If any person has received as the transferee of a vessel a properly endorsed certificate of ownership and certificate of number describing that vessel and the transfer fee has not been paid as required by this code within 30 days, a penalty of one-half of the transfer fee specified in Section 9855 shall be assessed.