Originally Posted by Amapola
To register a boat in Florida, you are required to pay sales tax or prove that you paid it elsewhere. It doesn't matter whether it is USCG documented or not.
When I registered a boat in Florida, the folks at the county tax office told me that since I had owned it for more than six months, there would be no Florida sales tax charged, just the rather reasonable state registration
I was not a Florida resident, and the boat had been kept outside the US for several years and had never been registered in any state.