It was discovered in 1982 by cavers in scuba gear negotiating tunnels for the first time."You've got to dive through a 230-metre-long tunnel of water to get to that section of cave totally submerged in scuba gear," Ms Mc Kinnon said."That is probably the best cave diving in Tasmania.
The rest are interesting, exciting and challenging but not what you'd call scenic."There are very few places now on this planet that you can actually explore, that you can be first; even if you are not the first, you can be one of half a dozen people who have been there."Some of these places are just amazingly beautiful or powerful and impressive.
Diving the numerous Nullabor caves is done in temperatures up of 20 degrees Celsius; in Tasmania it can be as low as 2C — a much chillier experience, adding to the adventure.
But adventure turned to tragedy near Ida Bay in 1990 when two high school students and a teacher died in flash flooding at Mystery Creek Cave.
Efforts started to turn to conserving and protecting caves.
Mr Kiernan returned in 1981 as the campaign against the dam was building.