California Code, Revenue and Taxation Code - RTC § 6294

(a) When an undocumented vessel required to be registered under the Vehicle Code is sold at retail by other than a person holding a seller's permit and regularly engaged in the business of selling vessels, the retailer is not required or authorized to collect the use tax from the purchaser, but the purchaser of the vessel must pay the use tax to the Department of Motor Vehicles acting for, and on behalf of, the board pursuant to Section 9928 of the Vehicle Code.

(b) If the purchaser makes an application to the department which is not timely, and is subject to penalty because of delinquency in effecting registration or transfer of registration of the undocumented vessel, he or she then becomes liable also for penalty as specified in Section 6591, but no interest shall accrue.

(c) Application to the department by the purchaser shall relieve the purchaser of the obligation to file a return with the board under Section 6452.

(d) If the purchaser does not make application to either department, or does not pay the amount of use tax due, or files a return with the board under Section 6455 which is not timely, interest and penalties shall apply with respect to the unpaid amount as provided in Chapter 5 (commencing with Section 6451).