There are some beautiful basins around some of the springs in Florida. Aren't there also some "sinkholes" or are those the same thing as springs? I am fine having light and air 100ft or fewer above me while I get better. I even had the idea of doing a scuba "float" down a river but something tells me that might be more dangerous / complicated than I am imagining.
I find the basins okay for training but kind of boring. Most are not very deep or very wide.