Located in Madison County, Thunderhole Cave is an offset sink from the Withlacoochee River and is privately owned by Tom Morris his permission is required to dive it. Some of Tom's requirements include having an Abe Davis and no scootering.

Entering the shallow entrance requires negotiating through a small opening and several rocks. During the summer months the sinkhole basin has an algae bloom hindering visibility.

The upper section is usually very clear but can sometimes have limited visibility. After following the mainline for about 500' you will be at The Well. The Well is shaped like a teardrop, with a width of 30' and length of 60'. It starts at about 65' and continues to a bottom depth of 120'. At the bottom of the well, there is minor restriction. 50' beyond the restriction is the T (marked with an old Goodman handle).

Going right on the T is downstream. You will 100% know by the flow going into the downstream side. You can count on at least doubling your time out from your time in. As one would expect, going left at the T is upstream. Both the downstream and upstream passages are uniquely different. The upstream passage has some huge goethite formations.