That's a question I had about registration. Here in Canada, registration is of Federal regulation, not Provincial (or by State). So basically, a boat here used to have a Federal registration number, like mine, that is good for all Canada Provinces (like 62D xxxxxx, in the same fashion as US boats and skis). But lately, they started doing like in the US: new numbers are now starting with provinces acronyms (Quebec = QC, British-Columbia = BC, etc.).
So, what happens when a boat is sold cross-states in the USA? You have to change the number? How is it done? Wonder about new Canada numbers too... like if I was to buy a used ski from Ontario (ON).
Benji.