Every inch of shoreline in St Thomas is public space... There are endless beaches in St Thomas, take your pick. Coki Beach(great snorkeling, more local, can get crowded) Morning Star Beach(close to port) Lindburg Beach (by the airport, kinda close to port) Honeymoon Beach (ferry ride, great beach) Frenchman Bay Beach (kinda secluded, no services) Bolongo Bay (No clue, never been there)
The list goes on....