Ad hoc nude beaches; aforementioned Passage Key. North end of Honeymoon Island (a 5 mile walk up the beach, if you don't have a boat). Anclote Key. Key ("Beer Can Island") just north of Fort Desoto (both accessable only by boat). See a pattern developing here? My 17' sailboat was always "clothing optional...but highly discouraged"; a mobile nude beach of it's own. NOTE: this was 10 years ago, when I lived there.