Jason Mallinson (with Charles Brickley, Greg Horne, Bev Shade, Rick Stanton & Bill Stone from UK and Soriano Antonio José & Gustavo Vela from Mexico). February-April 2001

Previous exploration of the submerged cave passages in the Santo Domingo canyon area of Central Mexico indicated the potential for a world record height difference between sink and resurgence. With this in mind, this team decided to utilise the latest technology in re-breathing equipment to eliminate the need for extensive cylinder re-filling and staging. Unfortunately progress in the Cueva Cheve resurgence was stopped by boulders after 1.5 km, and although dives in the Sistema Huatla resurgence found a continuation, progress was curtailed at an airbell after 300m when time ran out. Several members of the team exhibited symptoms of the fungal infection histoplasmosis, whose spores thrive in bird droppings in the soil.