Tank Cave

The Green Waterhole – Tank Cave system has a special association with the CDAA and has been an integral part of the CDAA’s training programs and focal point for the CDAA’s research, conservation and exploration activities for several decades. 

Tank Cave, which lies predominantly to the East of Green Waterhole features over 10 kilometres of intersecting phreatic passages. It is by far the longest underwater cave system in South Australia and the second-longest in the nation.

Access to the Green Waterhole – Tank Cave system is restricted to CDAA “Advanced-Cave” level divers, and it is often used for the final assessment dives for “Advanced-Cave” certification candidates. Ongoing exploration of Tank Cave in recent years has resulted in the discovery of several kilometres of additional cave passage, including, in 2018, the connection to Green Waterhole, and the fossil deposits at the systems Western extremity, located in the designated Green Waterhole – Tank Cave Fossil Complex.

The importance of Tank Cave to the CDAA resulted in the Association purchasing the land where the primary entrance to the system is located in 2010. Access via this entrance is managed by the CDAA. The only other known natural entrance to the system is via Green Waterhole, which is currently managed by the Department for Environment and Water [DEW]. In 1998, government recognition of the CDAA’s modern training programs and strict access protocols resulted in the responsible Minister reinforcing the State Government’s 1973 findings, with an ongoing directive that access to Green Waterhole be limited to members of the CDAA.

While the Green Waterhole – Tank Cave system lacks some of the spectacular attributes synonymous with the region’s other world-renowned sites such as Piccaninnie Ponds, the Shaft, and Kilsby Sinkhole, it is nonetheless one of Australia's most popular and frequently dived cave systems. Broader recognition of the subtle and sensitive nature of the system’s significant features, including the unique speleology and outstanding fossil assemblages located in the Western end of the system has recently resulted in the provisional State Heritage listing of the Green Waterhole – Tank Cave Fossil Complex. The CDAA considers these potentially vulnerable areas within the Complex to be worthy of higher legislative protection, in order to secure the CDAA’s role in future research, training, education and conservation initiatives.

Site Access Requirements:

• A suitably qualified Tank Cave site Access Officer is required for each day of diving.
• Property gate must be closed at all times.
• Familiarization schedule must be followed until completed. This schedule can be located in the photographs above.