I was there a couple years ago. Look up N2 the Blue Divers in Fredericksted. Definitely dive the Fredericksted pier with them. We also did several boat dives with them that were great. You'll see frog fish, sea horses and octopus, even on the daytime dive. The Frediericksted side of the island is almost alway glass calm. The shore dive at Cane Bay is great, and the restaurant across the road next to the dive shop is excellent. We left it for our last day, but would have loved to do it again if we had the chance. The Nature Conservancy has a big preserve at the east end of the island that makes for a really nice walk along an undeveloped bay, and the snorkeling in the bay is really nice. On one evening snorkel off our resort (Tamarind Reef) we saw 4 or 5 eagle rays, several turtles, an octopus, and literally a hundred lobsters. There were 12 under one ledge.