Hirschbrunn spring, Austria.
Periodic spring “Hirschbrunn” lies below the northern slopes of the Dachstein massif, on the shore of Lake Hallstatt, and diverts water from the eastern area of the cave Hirlatz, as well as near water spring Kessel. Part of Hirlatz with which spring have the connection is called Dosenfrass. Character of this cave is a very narrow passage throughout the whole profile, about 0.5 to 1 m wide, with mostly vertical orientation. Entrance was during the ’90 years swamped by larger boulders and if you stretch between them, it is still possible to access the surface. Their position is not stable, and sometimes it is changed due to high pressure water springing out. Using of sidemount kit here is recommended. Fins and buoyancy compensator are absolutely unnecessary, but the helmet with light can be very useful. When diving here, the equipment may suffer a lot.
Diving survey here began around 1990, in 1991 -45 m (Mayberg), 1996 Thomas Behrend -72 m (Trimix) and Czech divers with a few nice dives to -67 m with air. I started to dive here since 2000, and a year later I reached -72 m depth. In 2005, I managed to overcome restrictions at the depth of -75 meters and reached a depth of -80 meters, from where the tunnel seems to be still continuing further down in the usual shape.