In March 2018 we are mounting a two-month long cave diving expedition to return to the Cueva de la Peña Colorada. This expedition promises to be one of the most ambitious and challenging cave diving projects ever attempted. The current limit of exploration, reached by Bill Stone and the U.S. Deep Caving Team in 1984, is sump 7 which was explored to a depth of 55 metres. On this expedition the team had to turn due to the insurmountable logistics of using open-circuit diving gear in such a remote place. In the 34 years since this expedition no one has attempted to continue exploration in sump 7 due to the massive logistical challenges involved. Our team of world class cave divers will attempt to explore further in this remote place making use of the most high-tech caving and cave diving gear and techniques available to date.

The map of the Cueave de la Peña Colorada. The sump on the far left is sump 7 - the objective of this expedition.

Just to reach the start of sump 7 it is necessary to travel more than 5km underground. The route to the current end of exploration will involve technical climbing and rope work, negotiating the six previous sumps and camping underground for several weeks. In addition, sump 7 starts at the bottom of a 55 metre vertical shaft, without any dry place to gear up, adding to the challenge of exploring in this remote place.

We not only need to travel to sump 7 ourselves but we also need to transport a large quantity of technical diving equipment. We plan to equip our exploration divers with the latest in long range diving equipment including dual rebreathers, underwater scooters and a decompression habitat to ensure they have sufficient range and to cater for all eventualities. Combined with camping equipment, ropes and karabiners we estimate that we have in the region of 800 kilograms of kit to transport to sump 7, a truly monumental task.

To make this expedition possible we have recruited an international team of over 20 world-class cave divers capable of exploring this remote place. One of the challenges is that it is not clear if sump 7 will stay fully under water until connecting into sump 9 in San Agustin - the place we believe to be the source of the water in the Peña Colorada. If this is the case, the connection between sump 7 in the Peña Colorada and sump 9 in San Agustin could be the longest sump on Earth with depths of over 100 metres. On the other hand, if the sump surfaces and we find more dry cave, we would have to establish one of the most remote cave camps to date to continue exploration. Either way, exploration of sump 7 in the Peña Colorada will be epic!

A training dive in Madison Blue Spring via Martz Sink with Andreas Klocker, Zeb Lilly and Matt Vinzant. Andreas is logging hours on his brand new Kiss Sidewinder.