hi, yes i know about the cruise pools and we were on the magic in 2007 and his skin seemed to cope well with the boat pools however on previous trips vacation rental pools and some hotel pools play havoc, it must be the extra chemicals that they use. The salt water does seem to ease it a little and it means that he play happily without so much issue with his skin afterwards so i do try and find saltwater if i can not always possible though.
In terms of the best way to cope, cream, cream and more cream is the answer. I find on areas prone to wetness, face around mouth hands etc ointment works better as it does not get washed off. but basically cream in the morning, before the pool, shower and cream straight away afterwards tends to keep flare ups at bay. also in the warm avoid clingy material and tyr to stick to cotton as otherwise you may have a flare up of prickly heat as well as eczema to cope with like i did last april in florida, not a pretty sight and very uncomfortable