We took our daughters, ages 5, 7, and 9, on the Atlantis submarine excursion at St. Thomas, and we all enjoyed it!!! You take a 20 minute boat ride to Buck Island where you board the submarine. We saw many fish, sea turtles, a few small sharks, lots of coral and different terrain of the underwater world. We went down to about 80 feet in the sea. We didn't feel claustraphobic at all......it was nice, air-conditioned, and the guide was very knowledgeable.