The Sea Princess is a very nice ship with a nice Children's play area. I hope your son finds other playmates and enjoys the children's program. In Jamaica, book the 10 a.m. catamaran tour. It will give you plenty of time to have a nice breakfast and get your stuff together and if there is any adverse weather, it may clear bu them. (This happened on our trip; my adult son only could book the 10 and my friends had booked the 8:30. Well due to early morning rain, their trip was delayed and they never left until just before 10. They alll had a great time. Don't forget the aqua shoes or light canvas sneakers for walking the falls. Lunch is usually served on board at the buffet until 2 p.m. and I think even pizza till the same time, so you may be back. But, you can still order room service or tea time (little sandwiches and cookies) is usually around 4 p.m. Pick up some whole fruit in the morning or have your steward bring a basket to you cabin. Take the 8:30 a.m. Sting Ray City tour. Order room service the night before for breakfast if you think you are not able to get to the buffet early enough. The Sting Rays are more hungry earlier in the day and all passengers must wear flotation vests for safety, so your son should have no problem. Our ship tour had youngsters about his age and they had a wonderful time. Don't forget the sunscreen. There are only a few shops in Grand Cayman so your shopping will be limited. If you take a taxi to Seven Mile Beach in the afternoon, the hotel shops offer the Tourtuga Rum Cake (which is the island souvenir to buy, but it is heavy and pricey.) You are wise to just wait and see on Cozumel. Taking a taxi is very reliable there and a trip to the dolphin encounter may offer the best alternative for you and your family. Or just go to Playa del Sol which is a beautiful beach including a crafts bazaar, facilities and restaurant with great bargains on souvenirs. On your return you can always stop for a cool refreshing beverage and souvenir shopping down town. Enjoy Princess Cay too.