I have been to St. Thomas and St. Kitts from a cruise ship. The diving in St. Kitts was very nice. We dove with Pro Divers and they were great! We dove in St. Thomas on 2 different trips. The diving was ok. The first trip was in Nov 2010 and the vis wasn’t very good. The second trip was in October 2011 and it was a better experience. I definitely preferred the diving in St. Kitts over St. Thomas but I can’t speak to the land based activities. I’ll try to post some pics of both places later today.