Mexico’s Sistema Huautla is perhaps one of the most complex of the world’s deep caves. With 17 entrances and numerous independent and physically demanding deep routes, dropping nearly a mile into the earth, this dark labyrinth requires extensive rope work and multiple days of effort to reach the lower depths of the system. The last extension to the cave took place in 1994, when Dr William Stone used his self-designed CIS Lunar rebreather to pass what was then considered the terminal sump. Staging their dive from a portable platform suspended over a pool of water, the transiting a flooded tunnel and went on to discovered some 3.3km (2 miles) of new passage, but were ultimately stopped by Sump 9.(...)
Read more: UnderWaterJournal.com