National Geographic : 2004 Jul
GEOGRAPHICA flow of underground water with dye, drops 8,356 feet from the mouth of Cheve to the bottom of Mano. The record holder, Krubera (Voronja) cave in the republic of Georgia (see My Seven, February 2004), has been explored to 5,610 feet by a com peting group of cavers. And make no mistake, this is a com petition, a "gentleman's game," as Stone calls it. Dozens of elite cavers from around the world joined Stone at Cheve in 2003, when the team, rappelling through waterfalls (right), got down nearly 5,000 feet before being stopped by a passage clogged with fallen rock. They were back early this year in the dry season, when under ground flooding is minimal, to seek a way around the blockage. To improve the odds of suc cess, Stone and his team relied on GPS receivers and satellite phones to help locate unex plored cave entrances, and on rock drills to aid in vertical climbs. Stone, an engineering Ph.D. who works with robots and spacecraft in his day job, modified the drills, making them lighter and with longer battery life. He has also improved rebreathers (below) that recycle divers' breath for hours, facili tating exploration of watery passages. The equipment and the cavers have to be tough. Stone and his teammates endure mud, darkness, tight places, cold, and a sense of utter isolation. "You feel," he says, "like you're at BILLSTONE(BOTH) the absolute end of the world." With time running out in this year's expedition, the team found a cave with wind drafting inward-an indication of depth. It could be the connecting route Stone is looking for. He hopes to return for a full-scale assault on it, but there are complications. In March a British team became trapped in a cave northeast of Mexico City, and for now the Mexican government has restricted caving. "A lot of diplo macy is going to have to take place before any more exploration does," Stone says. -Chris Carroll CAVE RACE Stone and his inter national team of explorers sent back regular dispatches and images from their eight-week expedition to the center of the Earth. Find them at nationalgeo graphic.com/magazine/caverace.