I was also going to suggest Grand Cayman. Snorkeling is great, StingRay City is great. They have an excellent turtle farm...think tens of thousands of turtles....and I am sure your son would love it. There is really one road that runs around the entire island, and most of the hotels are centrally located on it. So, even though there are no all-inclusives, most of the restaurants are all in the same area. No need to go searching. It has all of your wants, and is beautiful.