A Montana scuba diver died on Saturday, 20 May, when his attempts to fill an air-bag in a lake appear to have resulted in a regulator freeflow.
The man was identified by the county sheriff's office as William Dreyer, 55, from Bozeman. With another diver from the same nearby town he had travelled to Canyon Ferry Reservoir, the state's third-largest body of water.
The two divers had descended at a site between two lake features, Cemetery Island and Hellgate Campground, at around mid-day. They were trying to raise a vehicle that had been lost through surface ice the previous winter, according to Lewis & Clark County Sheriff Leo Dutton.
He said that the dive-site was one of the deeper parts of the lake, where the bed was around 34m beneath the surface. Surface water temperature would have been around 14 degrees C.
According to Dreyer’s buddy, the divers were about two minutes into filling lift-bags with air when what was described as a possible regulator malfunction had occurred, with a freeflow draining Dreyer’s tank of air. He had then started to ascend but had stopped moving while still at a depth of about 29m.
His buddy reported having to attach a line to Dreyer to help pull him to the surface, where attempts to resuscitate him using CPR proved unsuccessful.
Highway Patrol and Fish, Wildlife & Parks staff were first responders to an emergency call, and a police investigation including post mortem medical and diving equipment examinations is now underway.
DCI incident in Orkney
Meanwhile a scuba diver was taken to a hyperbaric chamber with suspected decompression illness in Orkney on 21 May.
The diver had got into difficulty off the east coast of Stromsay island, with the Coastguard issuing an alert at around 3pm. Kirkwall lifeboat brought the casualty back to land, with an ambulance continuing to the chamber at Orkney Research & Innovation Campus on Stromness.
The incident occurred five days after diver Grant Wright went missing south of Orkney.