National Geographic : 1984 Jan
OOKS DECEIVE in the world of sinkholes. That is part of their fascination, and their great danger. Rigging a lifeline is crucial as Anne Doubilet, guide John McCormick, and I (below, left to right) gear up to probe the Pines. Spring Cave is its offi cial name, but pine trees in the commercially farmed Tanta noola Forest Reserve inspire its more popular title. As we stand in this drinking-clean water topped with duckweed, our precautions seem hardly neces sary. Yet the Pines is one of the most dangerous of the Mount Gambier sinkholes. A wide chamber opens beneath the limestone rim and plunges 20 meters (66 feet) at a 45-degree angle before sharply narrow ing. Only diving lamps break the darkness. I swam close to John as we squeezed into a cor ridor near the bottom, careful not to kick up disorienting clouds of ground silt. Eleven divers perished in the region's sinkholes between 1969 and 1974. Three died in a hole, now sealed, near the Pines. Two were lost in dark corners of Piccaninnie Chasm. The state government nearly banned all sinkhole diving. Instead, concerned divers formed the Cave Divers Asso ciation of Australia and were given authority to train divers in cave safety. No one lacking its certification can dive in the sinkholes. The rules sadden some older divers who don't want to retrain with the re quired modern equipment. "We were the original guides," says Phil Potter, who discov ered Piccaninnie Chasm in 1962. "Now we can't get in," But the association's work has so far ended cave fatalities.