St Maarten - St Martin has a fairly relaxed attitude towards beach nudity. The island is the leading Caribbean destination for nudists, with Club Orient on famous Orient Beach the resort of choice. Topless sunbathing is the norm almost everywhere, except at some resorts catering to a mostly conservative American cliental. The famous Sunset Bar & Grill at Maho Beach offers free drinks to topless ladies.
Even though the Dutch side doesn't advertise 'official' nude beaches, Cupecoy Beach has been for decades the Dutch side clothing optional spot. There are several remote beaches, where nobody will complain if you swim in the buff.
On the French side, there are many empty beaches and visitors can dress or undress as they please - again, nobody really cares - no matter what official publications state. Safe 'nude' spots besides Orient Beach are Baie Rouge and Happy Bay next to Friars Bay.