Through-trip in submerged mine

[ethanb]

Last weekend, Paul Lothary and myself (Ethan Brodsky) did a through-trip at a submerged mine in southwestern Wisconsin. The site has been discussed earlier on thedecostop (in ) and written up in  Advanced Diver Magazine (issue 5).

The mine was originally hand-dug, but later converted so that trucks could drive inside. The entrance ("adit") is a ramp that disappears into the water. After a short "spring run", a truck-sized tunnel enters into the side of a ridge. The main tunnel decends to about 65 feet, then slopes back up close to ground level (there is a deeper side tunnel with depths of ~100 ft that goes further than we've cared to swim in the 48 degF water). At the end of the main tunnel are a number of air-filled galleries. Our group has been diving the site since the late 1990s, but we still find new sections ocasionally. During a dive a couple years ago, someone noticed a bit of light visible at the top of a mud slope in one of the open-air rooms, at a point about 1000 ft from the main entrance. We tried using smoke-bombs and an observer on the surface to locate it, but were unsuccessful. Eventually we found an air-shaft that we believed to be the entrance.

Last weekend, Paul and I, aided by Tamara Thomsen (who was teached a cavern/intro class and could not accompany us for the dive), set out to do a through-trip, entering through the air shaft and exiting the main entrance.  We lowered our tanks into the shaft, rapelled in ourselves, passed our gear down the mud slope (through a low restriction that coated everything in mud), kitted up while standing in the stickiest mud imaginable, and dropped into the water to find the line only 20 feet away.

We did a bit of exploration near the new entrance (it feels so much "closer" now), then headed out, catching up with another team on their way out from a dive at the main entrance. They weren't really expecting us, so Paul gave Jason (the trailing diver) a big surprise by sneaking up (with his light covered) and grabbed his fin.

We discussed doing a return trip, but we were already a bit cold and weren't anxious to get our gear all muddy again (even though the dive had done little to wash the mud off from our initial entrance), trash our drysuits climbing through the restriction again, or to lift our tanks back out of the air shaft, so we called it a day.

As far as I know, this was the first underwater underground traversal of any length done in Wisconsin.

Ethan