What makes Blue Grotto unique is that it has an air bell. This air bell is located at about thirty feet deep. Back when Blue Grotto opened in 1965, the owner Tom McQuarrie wanted to take steps to ensure safety. Tom built a custom diving bell which has been replaced time and time again, as nothing lasts underwater. Check out more on the air bell here. 

Although Virgil is often in the shallows, divers can explore this cavern to depths of about 100 feet. There is an upper cavern and a lower chamber where there is no longer ambient light and you cannot see the cavern entrance. This has long been a popular dive site for training. In fact, I did some training here myself. 

Turtles like Virgil will spend almost all their lives underwater. They will go to land to bask in the sun and to lay their eggs. Florida softshell turtles forage well underwater using their large webbed feet (3 claws on each foot). Their diet consists of fish, frogs, insects, and crustaceans. This species of turtle has to be on the lookout for alligators. It also has to worry about foxes, skunks, and racoons going after their nests on land. Florida softshell turtles even have to worry about large birds grabbing one of their young. 

Florida softshell turtles can lay 4-5 egg clutches in a breeding season. Because of this, they have one of the highest egg production rates of any reptile. They are not considered at risk of endangerment. This species is commonly seen in Florida. It is also seen in Georgia, South Carolina, and Alabama.