Blue Spring State Park provides an ideal home for the West Indian Manatee or commonly known as the "Sea Cow" due to Blue Springs Run providing a constant water temperature of 22.2°C (72°F). The park is a designated manatee refuge, so the scuba diving season only lasts from 16 March to mid-November. If you are thinking about swimming with the manatees, you'll be disappointed to learn that this kind of activities is not permitted.
There are some regulations in place for health and safety reasons. Divers can only register with a partner, must be certified and cannot use any motorized underwater equipment. The good news is you can dive with an instructor, even if you don't hold a certificate. Although cave diving may leave you in the dark, using lights is prohibited at depths of 18 m (60 ft) or less.
For fees and more information, you can visit the Blue Spring State Park website.