Diver ran out of air while trying to untangle line
A diver ran out of air and drowned after volunteering to remove a heavy weight from his dive group boat’s tangled guide line, an inquest has found.
Diving safety specialist, Nick Bailey, who works with the UK’s Health and Safety Executive, said he believes John McNally, 46, from Bruff in Co Limerick, quickly burned through his air supply while working strenuously at depths of up to 20-metres to free a 25kg weight from a shot line — a weighed down buoy-marked rope used by divers to guide them on to wrecks — while diving on a wreck off Roche’s Point in Cork last July.
Mr Bailey said data from Mr McNally’s dive computer showed he tried to make a rapid 10-metre ascent in 10 seconds – six times faster than recommended.
He said Mr McNally stopped at this depth for a few seconds, before descending to the seabed again from where his body was recovered minutes later.
A postmortem established the cause of death was acute pulmonary oedema due to drowning associated with barotrauma (due to air pressure) while diving.
The jury at Cork City Coroner’s court returned a verdict yesterday of death due to misadventure.
Over two days of evidence, the inquest heard that Mr McNally had travelled with members of the Limerick and the University of Limerick (UL) sub aqua clubs on July 14, 2014, to dive with members of the Blackwater sub aqua club.
Blackwater member Matt Culloty, the dive officer on the day, said he paired diving buddies based on their experience and divided 17 men between two boats.
After safety briefings in Crosshaven, the group first dived on the wreck of the World War 1 mine-laying U-boat, UC42, which rests at the mouth of Cork Harbour — a dive Mr Culloty described as “textbook”.
“I have never seen such a perfect dive. It went perfectly. Everyone knew what they were doing,” he said.
The group had lunch in Crosshaven and returned in the afternoon to dive on the Star Immaculate 11, a trawler which sunk in 1993 in about 18 metres of water about 500 metres off Roche’s Point.
As divers returned to their boats, they had trouble recovering the shot line. The inquest was told it looked as if it had become tangled with the line of a lobster pot about 4/6 metres below the surface.
Mr McNally offered to dive again and free it but he entered the water without a buddy or safety check.
But the inquest was told that Mr McNally may have misunderstood the purpose of his dive, and may have felt he had to free the weight.
Limerick dive club member Eamon Maloney snorkelled and watched Mr McNally dive beyond the lobster pot and while he lost sight of him, he could still see his bubbles. The rope was freed and divers on the boat pulled it up.
But Mr Maloney said he saw a burst of bubbles suddenly before they stopped completely.
“I shouted to the boat ‘I can’t see his bubbles and this is taking too long — get divers in the water immediately’,” he said.
Blackwater sub aqua club member Mike Reidy recovered Mr McNally’s body from the seabed within minutes, 10 metres south of the wreck. He noted his air tank was empty.
Limerick dive club member Dr Tom O’Donnell, a former medical advisor to the Irish Underwater Council, said Mr McNally was limp and unconscious when he was recovered to the boat.
The alarm was raised and when the onboard defibrillator failed, Dr O’Donnell administered CPR as the boat sped towards Crosshaven. Paramedics waiting on shore restored Mr McNally’s pulse, before he was rushed by ambulance to Cork University Hospital where he was pronounced dead a short time later.
