Hi i have an 8-year old and a 12-year old and last year we went on teh disney cruise and we are going again next week.My 12-year old daughter got seasick for about a day but she got used to it so dont worry and try to get some medication for seasickness.But most of all dont worry he will be fine.

I went on a Disney cruise this summer, I couldnt even feel that we were on the water. Its all in your mind if you get sea sick. The fisrt night on the boat everytime I looked out I was like.. .. ..woah, but I got used to it. Your little boy will be fine, im sure.
hope this helped (a little)

A disney cruiser