They were able to better a record set by an American team that ventured 25,591 feet (7,800 meters) into a cave system in Florida. The British team did not only have to deal with the psychological effects of being 28,953 feet (8,825 meters) from the nearest exit, but also with water temperatures of 52 degrees (11 degrees Centigrade).
Rick Stanton was one of the lead explorers of Wookey Hole Caves, a show cave and tourist attraction in the village of Wookey Hole. Over the years, he and other British cave divers did set depth record after depth record in the system near Wells in Somerset, England. In 1977, Martyn Farr reached 148 feet (45 meters), followed by Rob Parker in 1985 (223 feet/68 meters), and John Volanthen and Rick Stanton. The later team did reach 249 feet (76 meters) in 2004, and 295 feet (90 meters) in 2005.
Jason Mallinson is also a very experienced British diver. In 2008, Mallinson and Phil Rowsell explored BU56, a deep cave system in the Spanish Pyrenees that was discovered was once regarded as the deepest cave on the planet.
Rene Houben is an IT specialist from Groningen in the Netherlands. He did explore the Doux de Coly Cave in the Dordogne region of southern France in June 2010. He did also set a previous record exploring Pozo Azul when he and John Volanthen reached 14,419 feet (4,395 meters) in the cave.
An excellent YouTube video shows a different team exploring the Pozo Azul cave system in 2008 is available here: