I did this with my familiy including two children 7&4, it was part of an Island tour including the submarine and the Turtle farm and a visit to Hell! (the town).
The submarine was moured in shallow water a mile or so out from the land, you went ot it on a glass bottomed boat, it moor up against the Sub and then a diver went outside in the sea and encouraged Stinrays etc to go past.
It was good the trip was nice nad the views were loverly, in the sub its a bit cramped and gets hot quickly.
The turtle farm was good with our familiy holding the Turltes and we were also given a tour of the coast.
