A little late (shouldn't be leaving for Mx in May anyway LOL) but have had experience with Calif tax guys. They are aggressive, but like everyone here states, if you are honestly transiting and have documentation to prove it, they will back down. But, they may require lots of documentation so save everything, all receipts, bills, contracts etc. We bought a 70 fter in Fl. and Documented in Hawaii (we have a home there) and had papers sent to our Calif home address (yes we knew Ca would question this but we knew we were being honest). They survey all documentations. We had all the paperwork to show that the boat was bought in Fl, moved to Ga. then cruised the carribbean and never planned to or entered Ca. waters. After a year they dropped the case but we were required to provide proof of dockage, fuel etc costs outside Ca. FYI, buying in Fl you have 30 (or 60 can't remember) days to move vessel or you owe Fl sales tax. Moving to Ga. they didn't care, no sales or property tax (only left boat for 6 months so not sure if you leave it for years). Documenting in Hawaii would required property tax if or when you entered Hawaiian waters. Totally legal. This is a case where documentation paid for itself.