Sistema Sac Actun was discovered in 1987. The first map of Sac Actun and tales of cave explorations are reported in AMCS Activities Newsletter #17 (December 1988). Further explorations and the eventual connection of Sac Actun to Sistema Nohoch Nah Chich are reported in AMCS Activities Newsletter #30 (June 2007).
Explorations in Sistema Actun Hu began in January 2007. Aktun Hu cave was surveyed to include the Cenote Outland cave. Outland was first explored by Mike Madden in 1992. Mike's explorations were abandoned due to logistical and landowner issues. Explorations in Aktun Hu bloomed during 2008, 2009, and 2010. The Hu exploration team certainly told the world
For the enthusiasts of pure underwater cave survey, Sac Actun has a 215246m length and a depth of -71.6m. Since a cave is a cave whether it's filled with water or air, the total length of Sac Actun including all wet and dry passages is 217363m (depth of 77.6m).
This new length for Sac Actun, 217363m, is a bit longer than the reported 217133m length of Wind Cave (NP) reported by Rod Horrocks on the NSS GEO2 cave page at this date. Having a 230m surplus of surveyed passage over Wind Cave is hardly a significant length advantage for Sac Actun. I expect the Wind Cave explorers to make up this difference quickly. I also expect further explorations to find an ever evasive connection from Sac Actun to Sistema Dos Ojos.
Again my congratulations to all cave exploration teams in this area.
Jim