46 CFR 67.111 - Assignment of official number.
(a) The owner of a vessel must submit an Application for Initial Issue, Exchange, or Replacement of Certificate of Documentation; or Redocumentation (form CG-1258) to the Director, National Vessel Documentation Center, to apply for an official number for the vessel when:
(1) Application is made for initial documentation of the vessel; or
(2) An existing vessel has been severed, with two or more vessels resulting. In this case, the official number of the original vessel is retired and the owner of each resulting vessel must apply for designation of a new official number.