WILLISTON SCUBA FIELD GUIDE
Descend into Florida’s Freshwater Cathedrals: Blue Grotto to Devil’s Den
A five-hour scuba outing with Harness Eco Tours that visits Blue Grotto’s open basin and cavern and the underground Devil’s Den spring; participants must be open‑water certified.
Descend into Florida’s Freshwater Cathedrals: Blue Grotto to Devil’s Den.
Dive into Florida’s Blue Grotto, a vibrant freshwater haven where clear water, resident fish and a friendly turtle await in a broad open basin, then move beyond the basin into a large upper cavern before finishing in the underground expanse of Devil’s Den Prehistoric Spring.
Highlights
Outing Highlights
Blue Grotto’s Open Basin and Resident Life
Blue Grotto’s large open basin drops to about 40 feet, features three large platforms for skill work, and is home to plentiful fish and a resident turtle for divers to meet.
Upper Cavern and the Air Bell
Behind the open basin a large upper cavern offers deeper water—down toward 60 feet—and near its entrance an air bell is maintained with breathable air pumped from the surface.
Devil’s Den Prehistoric Spring
Devil’s Den sits inside a roughly 120‑foot‑wide cave and, like Florida springs generally, holds a constant 72‑degree water temperature year‑round.
What the day feels like
What the Day Feels Like
Over a roughly five‑hour outing you begin in Blue Grotto’s sunlit basin—using platforms to brush up on skills, observing local fish and the site’s turtle—then descend into the cavern’s deeper spaces before entering Devil’s Den’s subterranean spring, where the temperature holds steady and the cave opens wide.
Suitability
Who it's for
Who this trip suits—and who should sit this one out.
Practical planner
Details to review before reserving
The outing is organized as a roughly five‑hour experience.
No specific gear checklist is provided in the trip data; confirm rental and equipment details with the operator.
Devil’s Den maintains a constant 72‑degree water temperature year‑round.
Review cancellation policies before reserving.
Frequently asked questions
Planning Your Outing
Do I need scuba certification to join?
Yes — participants must be open‑water certified divers or above.
How long is the outing?
The trip is approximately 5 hours in total.
What depths will we reach at Blue Grotto and the cavern?
Blue Grotto’s open basin reaches about 40 feet; the large upper cavern area goes to around 60 feet.
What’s notable about Devil’s Den’s water and cave?
Devil’s Den is set inside a roughly 120‑foot‑wide cave and, like Florida springs, keeps a constant 72‑degree water temperature year‑round.
Who operates the Blue Grotto & Devil’s Den outings?
The trips are run by Harness Eco Tours.
Where are these sites located?
These dives take place in Williston, Florida, United States.