Castaway Cay has lots of fun for the kids:
1. Snorkeling with the kids.
2. Renting floats and going out to the jump/play area out in the water.
3. Groupers-it is an open air game area on the island. There are giant checkers and chess, shuffle board, pool, football, basketball and so forth.
4. I believe there is a dinosaur bone dig at scheduled hours on the island.
5. At the lunch buffet on the island there are cookies and ice cream to eat.
Nassau:
1. Visit the pirate museum.
2. Visit the Del Sol Store. They sell t-shirts, jewelry and misc. items that change from invisible designs to brightly colored designs.
3. There is a McDonalds on the island if you need a quick break.
4. A day at Atlantis should be fun.
Enjoy your cruise!!