Cal. Veh. Code § 9902

The department, upon receipt of a properly endorsed certificate of ownership and a new application form and the required fee, shall issue a new certificate of ownership and a new certificate of number in the same manner as provided for in the initial issuance of number and the number may be reassigned to the new owner, provided, however, in the case of a transfer of a part interest which does not affect the owner’s right to operate such undocumented vessel the transfer shall not terminate the certificate of number.