Historical technical training references at 40 Fathoms Grotto.
United States of America
Guided training sinkhole with dark green water.
Guided training sinkhole with dark green water.
Dives are typically run by the operator or staff-guided training teams.
40 Fathoms Grotto is a commercial-training sinkhole near Ocala, Florida with dark green freshwater and a man-made underwater playground of boats, motorcycles, a mini-sub, and platforms. It is technically open but effectively restricted, so it suits experienced divers who want a guided training site rather than a casual recreational drop-in.
Site Conditions
Safety Notes
Expect limited visibility, guide-led access, and depth planning that matches your training level.
Access Restrictions
Primarily used for commercial dive training; public access is discouraged.
Legal Notes
Technically open due to contractual requirements, but pricing and staffing are intended to limit casual recreational use.
Community notes to help plan your visit.
Scuba Diving
Commercial training sinkhole with man-made features and guided access.
Research estimate
Research estimate
Research estimate
Last Updated
Research Sources
Historical technical training references at 40 Fathoms Grotto.

Freshwater spring cavern with a training-friendly basin.

Contained Florida spring dive with clear water.

Rainbow River at KP Hole Park is a clear spring drift.