LOCATION: (lat. 28°25'32.2" N., long. 82°34'42.1" W.)
To reach Arch Sink from US 19 turn east onto County Line Road for 3 miles then south on Kelly Road 1/2 mi. Arch Sink is in the depression to the right of the curve.
The water in this elongated pond is usually blue to blue - green, a trait shared by at least four other sinks in close proximity. The distinctive natural bridge or arch of limestone extending across the pond is usually submerged, but is sometimes exposed during times of drought. Visibility is usually 20ft or less in this system except for the upper ten feet of the dome room and the very back of the shallow tunnel which both contain warmer water increasing vis up to 100ft . This warmer water invades the entire system for only a few weeks each year around Oct & Nov providing a spectacular dive!
Upon entering we dropped down 12ft and made our way under the arch to the permanent line attached on the south wall at a depth of 15ft. Decending to 45ft the line splits in three separate directions, each following the slope of the mound downward. We chose the northwesterly line and made our way single file through the boulder sized breakdown that restricts the entrance to the main cavern. Once inside, the line split, marking the beginning and end of a circuit around the cavern. Since a clockwise tour is the preferred route, we hit the deep section first and spent the rest of the dive in shallower water. Heading down left hand line, we immediately came to a "T" going almost straight down a steep shaft, leveling off at 185ft through a restriction into a tight room with a depth of 197ft. Back up into the clear water of the dome room we checked out the fossilized vertebrate remains in the ceiling , finished the circuit and exited the main cave. Choosing another line at the "split" we went into the shallow tunnel, nice ceiling formations and clearer water about 250ft in, shining our lights at the trapped air bubbles on the ceiling produced an awsome mirrorball effect on the walls and floor of the cave. The third line went about 60ft into a small room, found some more fossilized bones in a horizontal crack .
Aerial View Of Arch Sink
Map Of Arch Sink
Restricted end of the shallow section
Rust colored lattice formation in ceiling of shallow section
Fossilized dugong ribcage emerging from ceiling of dome room