We are considering a Royal Caribbean cruise on Mariner. Are the swimming pools fresh or salt water?
If you have a young teenage boy who went in one of the swimming pools, what did he think about it? Did he swim alot or do the other activities?

To my knowledge, Princess is the only line that uses freshwater pools ...

In my experience, the pools can be pretty crowded particularly on sea days with nice weather. They also aren't olympics sized so it's more for splashing around then swimming. Still, if your son is a fan, bring a couple of suits so you'll always have one dry.