Hello!
My two sons (11 and 8 at the time) and I did the Atlantis Sub excursion in May/01. The kids loved it, but I wasn't as impressed as they were. I had been expecting a lot more vibrant sights. My first and only experience with underwater anything was in the Cayman Islands, and I was spoiled by the beauty of the ocean life there, I have been told that it is only second to the Great Barrier Reef...As for the kids....they thought it was great...the sub is a bit confining...but the crew was fun, and I think that your children would enjoy....hope this helps a bit...
Melissa