Sheck Exley donated approximately four acres containing Cathedral Sink to the National Speleological Society Cave Diving Section. The property is the furthest upstream of 18 known entrances into the Falmouth system that eventually empties into the Suwannee River at Ellaville Spring within the Suwannee River State Park. The system was explored and mapped by Sheck Exley, Mary Ellen Eckhoff, Paul DeLoach, Dave Fisk, L. Hall, John Harper, Lewis Holtzendorff, Randy Hylton, Bill Main, Clark Pitcairn, Wes Skiles, Bill Stone, Dale Sweet, John Zumrick and Court Smith, and contains over 41,020 feet of passage. On December 16, 1990, Sheck established what was then a record penetration of 10,939 feet on a multi-stage dive lasting nearly 12 hours, including decompression. (Upstream exploration was extended to over 17,000 feet in 2004.)

When exploration first began in Falmouth-Cathedral System, the visibility in Cathedral was often 100 feet or more. Since then, changes in the aquifer have reduced visibility to only a few feet most of the year. Occasionally, conditions allow the visibility to improve to 40 feet or so. Because of this, and the depths involved, Cathedral is considered an advanced cave dive with depths to 200+ feet and the access policy is written with this in mind.