It is one of the deepest fresh water sites in Europe and is already a popular attraction for scuba divers, but has a history of diving accidents.
Fred Buyle has become the first free diver to reach a depth of 65m in fresh water.
Since its closure, the former Dorothea Quarry has filled up with more than 100m of water.
It is one of the deepest fresh water sites in Europe and is already a popular attraction for scuba divers, but has a history of diving accidents.
Mr Buyle held his breath for more than two minutes to reach 65m unaided and beat the current world record of 63m.
The underwater visibility was nil below 15m and Mr Buyle dived in water temperatures of four degrees centigrade.
A huge safety operation was put in place and organisers are stressing this is not something to be attempted without expert instruction.
'Always risks'
Howard Jones from Free Dive magazine, who organised the event, said every safety precaution had been taken to ensure Mr Buyle came to no harm.
"There are always risks whenever you put your head under water," said Mr Jones.
"We had safety experts here, a doctor and paramedic and the most up-to-date safety equipment and four of the UK's top free divers on the surface.
"We had every safety measure possible to ensure we can deal with an incident very quickly."