Blue Springs is a state park, located in Orange City, FL; about an hour's drive from Disney World. It's one of many fresh water springs in the state. The "boil" is the center attraction for divers. Apparently due to the current drought, the water level is lower than normal & in turn the current is stronger. Depth is about 55ft for open water diver. A shaft extends further, to a depth of 120ft, but you must be a certified cave diver to explore. This is a great place to encounter Manatee in the winter.