Apopka Spring is a second-magnitude spring that discharges from a bowl-shaped depression about 5 to 6 feet in diameter below the central part of the pool. The vent opening is about 40 to 45 feet below the water surface. An underground cave system has been recognized for Apopka Spring. The vent opening narrows vertically downward into the limestone for 16 feet, where it then slopes northward at about 45 degrees to a depth of 90 feet, making for dangerous diving conditions.
The circular spring pool above the vent is about 180 feet in diameter. When spring flow is high, the spring discharge pool is clean and clear, but when flow is low, murky lake water may cloud the pool. When the lake is still, a gentle boil can be seen at the pool surface over the vent. Emergent vegetation and an organic, mucky bottom surround the pool perimeter in the cove area. Gourd Neck is buffered by marsh and lowland swamp forests toward the west; the east side of Gourd Neck is bordered by sandhill pine trees.