(Been there. Done that. Naked.)
Parents be warned. We had a sail boat growing up. Nothing too grand, just a 24 footer with a small cabin. For a few years we had it moored in a river near the ocean. It was about a mile from the mouth. My brother and I would usually take our female companions out there. Just row out and sit on the boat. Summer night, a few beers, skinny dipping ensues....you know the rest. No chance for the cops to get you. Complete privacy at night. Those were the days.