After the 1994 expedition to San Agustin attention moved elsewhere for almost 20 years until a reconnaissance expedition lead by Chris Jewell visited the cave in 2012. Their aim was to set themselves up for a large scale expedition in 2013, to tackle sump 9 ‘The Mother of all Sumps’. Over the next year Chris organised an international team of over 40 cavers, to make the dream of exploring ‘beyond the most remote point yet reached inside the earth’ a reality.
The team utilised the village of San Agustin as its base camp, as has been the case for past expeditions. Within just a few days the team had a route down the iconic San Agustin cave rigged ready for mass equipment moving. As soon as the rigging was complete, diver Jason Mallinson was ready to go and managed to re-line the sump all the way through to Camp 6. This was the camp established by Dr. Bill Stone and Barbra am Ende in 1994. Next all the equipment required for a 5 man team was transported down the cave and then finally through the sumps in specially constructed drytubes.
The dive team was comprised of two exploration divers Chris Jewell and Jason Mallinson plus a support team of John Lillestolen, Rich Hudson and Mirek Kopertowski. This team explored over 1.7 kilometres of dry cave passage whilst the divers reached a distance of 440m meters and a depth of 81 metres in sump 9. At this depth exploration was halted due to the gas mixture which had been selected for the effort.
Renewed interest in San Agustin prompted Huautla veteran Bill Steele to join the expedition for the final few weeks. In this time his small team discovered over 500 metres of new dry passage in upper reaches of San Agustin, demonstrating that there was plenty of potential for new discoveries left. The encouraging results laid the ground work for further expeditions to San Agustin and the creation of PESH (Proyecto Espeleológico Sistema Huautla).