I'm diving in one this weekend. Vortex Springs near Destin Florida, DeFuniak Springs Florida to be more precise. The water is deep enough to certify AOW divers (60ft min). Its actually much deeper though. Its clear and around 70 degrees year round. We take divers here because of the visibility. If you start early in the day its very clear. If you go late in the day the silt get stirred up and vis goes down. Its a busy place, Multiple dive instructors use the Springs, We are taking 40 plus divers this weekend , OW, AOW, and Rescue. It's going to be a busy and fun time. As far as how it differs, depends on the types of diving you normally do. The Springs are fresh water so less weight is needed compared to salt water, but you will need a 5 mil exposure suit which requires more weight than diving salt in tropical warm water with a swim suit.