Todd and Eric are both right on the registration deal. The issue is "public waters". If you sail in the ocean exclusively the boat does not need to be registered or titled, ocean is not "public waters" in that sense. Its when you sail inland that it changes. My trailer is titled in NC, boat is not. I sail offshore in SC 99% of the time. Since I can say the boat resides in NC or SC depending on where I am when asked, I have no numbers on the boat.