I recently registered in NY as well as being documented just to avoid the potential hassles. There is no requirement to have large, intrusive state registration numbers on a documented vessel in NY, just a little sticker. In NY there IS a state reg. requirement but I've never heard of anyone enforcing it. I understand that FL is indeed writing tickets. Surprise! Even if you can beat the ticket, I'm not prepared to hire a constitutional lawyer to contest it or to waste my valuable time on idiots. Just one more little example of losing freedoms bit by bit. It's inexpensive to register. You gotta pick your battles.
Stumble, I have a friend who bought a documented boat in NY (this was years ago)and moved it immediately to NJ. It was a private sale. The NY Sales tax office sent him a bill long afterward. They did find out somehow that the sale had taken place. He placed the bill in the circular file and never heard anything more but there is some way NYS got the info., apparently through the transfer of documentation. It would seem that there is some state notification when a transfer of documentation takes place.