Upon application for renewal of registration of an undocumented vessel, the applicant is required to furnish the hull identification number if the records of the department do not contain such number. If the vessel does not have a hull number, the department may assign an appropriate hull identification number.
Source:
Section 9871.5, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH§ionNum=9871.5..