Manatee Springs cave system

The cave system behind Manatee Springs, a first-magnitude spring on the lower Suwannee River, with more than 5 miles of mapped passage reached from the main spring, the Catfish Hotel and Friedman Sink under daily diver limits.

Manatee Springs is one of Florida's first-magnitude springs and the largest single spring flowing into the Suwannee River. It lies in Manatee Springs State Park near Chiefland, where a boardwalk runs through cypress forest beside a quarter-mile spring run. Beneath the spring is an extensive maze of passages that certified cave divers have helped map for more than 5 miles.

Three entrances are used. The main spring is open to open water divers and to cave divers. The Catfish Hotel, a sinkhole named for the bottom-dwelling fish that gather in it and often covered in duckweed, is the usual starting point for cave dives and is also used for cavern diving. Friedman Sink is reserved for divers with full cave certification.

The park strictly limits numbers: a set count of open water and cavern divers at one time and per day, and separate small limits for cave divers at the Catfish Hotel and Friedman Sink. Diving is first come, first served, with no reservations. The caves are home to the cave crayfish Procambarus lucifugus and Hobbs' cave amphipod, and manatees shelter in the spring in cooler months.

Florida State Parks gives an average flow of 50 to 150 million gallons a day. When the Suwannee River floods, river water can rise high enough to submerge the boardwalk, and dark tannic river water fills the spring run and greatly reduces visibility. The spring stays at about 72°F (22°C) year-round.

Manatee Springs was designated a National Natural Landmark in 1972. Cave divers' mapping has also added to knowledge of how water flows through the spring, according to the park.

Constant 72°F (22°C). During Suwannee River floods, tannic river water backs into the spring run and visibility drops sharply. Manatees use the spring in winter and divers must keep 50 feet away from them.

نطاقات اعتيادية من مصادر منشورة، لا ظروف آنية.

Three diving entrances are named by the park: the main spring (open water and cave divers), the Catfish Hotel (open water, cavern and cave divers) and Friedman Sink (full cave certification only).