Vortex Spring, Natural spring and dive site in Holmes County, United States

Vortex Spring is a cold freshwater spring near Ponce de Leon, Florida, whose 200 ft basin has sloping sides and feeds a cave linking it to the Floridan aquifer. It discharges about 28 million US gallons daily at a steady 68 °F with no thermocline. The runoff flows into Otter Creek; large carp swim in the basin and freshwater eels live in the cave.

In the early 1990s, 13 divers died while exploring the cave, prompting the state of Florida to threaten a ban on diving near cave entrances. Local divers responded by creating a special cave diving certification, and Vortex Spring installed a locked underwater gate at the hazardous section, opened only for certified divers accompanied by staff. In 2010 diver Ben McDaniel entered the restricted zone and never resurfaced; his body was not found.

Vortex Spring is a training site: two submerged platforms at 20 feet host Open Water certification dives, and an inverted metal "talk box" traps air so divers can speak to each other underwater. Large carp swim in the basin, while freshwater eels live in the cave.

The property has a full dive shop, camping areas with hookups, and training programs for different certification levels. Visitors should check what equipment is available and which qualifications are needed before arriving.

The cave has been surveyed to 1,642 feet, but a steel grate blocks passage beyond 310 feet; certified cave divers may go to 115 feet. An inverted metal "talk box" traps air so divers can remove their regulators and speak underwater. Freshwater eels live in the cave, while large carp swim in the basin.