Multi-day (2-day and longer) tickets expire 14 days after the first day is used, and the first use must be by December 31 of the year after they are purchased. So if you buy a multi-day ticket in 2017, you must begin using it by December 31, 2018 and it will expire 14 days after that first use day.
Dive Site Blue Grotto Dive Resort - Williston, FL. Blue Grotto is the largest clear water cavern located in the heart of freshwater spring country in Williston, Florida. The Blue Grotto lets you dive down to a depth of 100 feet (30 meters) in crystal clear water all the way down at a water temperature of 72 degrees Fahrenheit (23 degrees Celsius) all year round.
Blue Grotto is actually a sinkhole with good visibility. Depths reach 100 ft. Upon entering the sink you will encounter a very large cavern with writing on the walls. At a depth of 30 feet there is a fresh air bell so you can take off your mask and breath some fresh air. Continuing down, there is a large shaft that slopes down at a 90 degree angle. At around 90 feet you will encounter silt that can be easily stirred up. There are lights at 30 ft to illuminate the cavern. The owner, is very friendly and also manufactures dive, wreck and video lights.