Per FGS Bulletin 66:

Type: Spring
County: Levy
Lat/Long: 29 29 22.20119 82 58 36.73866
Manatee Spring and its run are on the east side of the Suwannee River within a densely wooded, lowland floodplain. The spring discharges into a conical sink depression. The spring pool measures 60 ft (18.3 m) north to south and 75 ft (22.9 m) east to west. The depth of the spring pool is 25 ft (7.6 m). The bottom of the spring pool is sand with numerous submerged logs. There is a limestone ledge 3 ft (0.9 m) below the water surface and a vertical wall on the south side of the spring pool where wooden steps lead down into the water for swimming access. There is a tremendous boil associated with this spring. Thick algae cover approximately 75% of the limestone ledge and wall. The water is sky blue. Native aquatic grasses inhabit the spring run. There are many cypress trees and knees on the north and east shores of the spring pool. The spring run flows southward to the Suwannee River approximately 1200 ft (365.8 m). A boardwalk follows the run to a dock at the mouth of the run on the Suwannee River. Uplands on the south side of the spring rise to approximately 15 ft (4.6 m) above the water level and are developed into a recreation area underneath a thick canopy of live oak and pine. There are numerous walkways and a rock wall along the south shore of the spring pool. The north shore is relatively pristine and wooded. An extensive underwater cave system has been mapped at Manatee Spring. Divers report that entry into the cave against the current is very difficult.

 Bill’s Description:

In the winter when the river rises, the flow diminishes and visibility is in the 40’ range. Visibility in the summer, on a good day is around 10’ to 15’.   It is a very large cave, great for scooters. The most popular traverse is from Friendman Sink to Catfish Hotel.