RCCL has a great kids program he will have a really good time. My son is 6 he had a blast never really wanted to be with us not by my choice. RCCL offers childrens dinner on formal nights you have to sign up the day before ask when you board the ship that is if your son would prefer to eat with the kids and not dress on formal nights. The program is ranged by age so he will not be with the little kids and will do things that will interest him. They will ask you if he can come and go on his own that is up to you. As far as in port there are a lot of different opions depending on where you are snorkeling, sailing, beaches, etc... or they usually offer services if your child would rather stay on the ship. I think he will really enjoy it. This time I bought a photo album and I am going to give my son a camera so he can show his dad/stepmom and his class his vacation.