We really enjoyed the submarine in Grand Cayman!!!! It was beautiful cruising along the coral wall! The sea life was abundant and colorful. We are glad we did it, and you don't even have to get wet. It is not something you would do a lot, but I was very glad we did it once! We then went snorkeling at Eden Rock, and it was fantastic!
We went down 110 FT in Grand Cayman on the Atlantis sub. The barrier reef/wall is the next most beautiful after Austrailia. I highly recommend this dive and only at this island. The other tour at Grand Cayman would be swimming with the Sting Rays. A once in a lifetime opportunity.
We did the Atlantis submarine dive in Cayman Islands last Oct. It was beautiful, interesting, and worth it, but if you are the least bit claustrophobic, or have trouble breathing in heat and humidity (asthmatic), then I suggest you pass.