No matter what time of year you travel, there will always be other children on board the Voyager class ships (particularly those within your children's age range). Personally, I have found Royal Caribbeans's Adventure Ocean Youth Program to be the best afloat. They divide the children in to 5 age categories (3-5/6-8/9-11/12-14/15-17) which allows for more age appropriate activites within age group. Carnival's (as are most of the other cruise lines programs) is divided into 3 groups. I never understood the logic of lumping childern 13-17 into one age group as they are certainly at totally different developmental and interest levels. That is just one aspect of the program and I would certainly be happy to answer any other specific questions you have about the youth program, but rest assured your children will love the program.