I don't remember if the Voyager class ships have salt or fresh water. I think it is salt. But as far as activities go you have the widest choice of children's activities on those ships. They also have a professional ice show which is really very good. All major cruise lines (except for the very upscale Crystal, etc) have bingo, movies, etc. It comes down to what your kids like to do. Some kids love action and some kids love activities. For instance, my son loves to rock climb, jump in on a pick up basketball game, ice skate, etc. My other son loves planned group activities like scavenger hunts, games, etc. (he is only 10) For teens the Voyager ships are amazing. And don't forget the Johnny Rockets restaurants on board. They offer hamburgers, hotdogs, fries, shakes, etc. with a rock and roll theme. I hope you have a great vacation.