What I have read is that they have to 48 inches , etc... but since my twin boys who are just 48 inches are not really "swimmers", I need to know how deep the pools that you land in when finishing the slides.
Some are 4 feet and up but some slides are only inches like the 8 lane race slide at BB and the summit plumet etc. You can have them wear lifejackets you can bring your own or get them at the waterpark.