[overbored]

in California you can either register with the DVM or document the boat. If you register it then the DMV will collect the use tax at that time. If documented then the state sends you a bill for the use tax about 6 months after the sale for any boat documented with a California address

 

[overbored]

In California you will pay use tax on boat unless it is sold by a dealer that has a sellers permit and then he collects sales tax. The DMV will charge you the use tax and it does not matter where you use the boat. the dmv does not have a sellers permit so they can not charge you sales tax, they collect the use tax for the BOE. buy the boat and document it with the HI address. stay away from the DMV. if CA wants there tax they will send you the bill and the first bill will not have any penalties if you pay it on time
FAQ - Use Tax on Purchases of Vehicles, Vessels, Aircraft - Board of Equalization