The Baths of Gorda were offered when I ported in Tortola....we had to take a short ferry ride over.....
So I assume it will be offered when we port in St. Thomas?
BTW, last year when I went to Turks & Caicos it rained lightly :{ But we were absolutely freezing on our mini-boat adventure and we weren't allowed to snorkel....however, there's a Margartiaville restuarant right at the dock, which also has a huge pool and a beach area....so we were still able to party and swim....