Divers’ death ‘tragic and avoidable’, Brisbane coroner finds

Fisheries Queensland director Andrew Thwaites’ death during a recreational Morton Island scuba dive in August 2016 was “tragic and avoidable”, a Queensland coroner has found.

Handing down her findings into Mr Thwaites’ death, Coroner Christine Clements said it was hoped lessons would be learned to prevent similar tragedies.

Both experienced divers, Mr Thwaites, 44, and his partner Kelly-Anne Masterman had joined a group of recreational scuba divers from their diving club on a day trip to the eastern side of Moreton Island on August 10, 2016, on a day of “perfect conditions”.

On their second dive of the day, at about 22 metres underwater, Mr Thwaites indicated to Ms Masterman that he wasn’t feeling well and wanted to surface.

As they rose through the water, Ms Masterman said she lost sight of Mr Thwaites about 15 metres from the surface.

Fellow divers on the boat’s deck saw Mr Thwaites on an anchor line briefly before he disappeared, but assumed he had simply dived again, not realising he was in trouble.

Mr Thwaites was not seen alive again.

Police divers recovered his body the next day from the floor of the sea-bed.

In handing down her findings over the tragic incident, the coroner found Mr Thwaites died of carbon monoxide poisoning that caused him to fall unconscious and drown.

Mr Thwaites’ second air tank had 2,366 parts per million of carbon monoxide, far above the recommended upper level of five parts per million.

“Increased pressure at depth increases the partial pressure of both the toxic gas and other gases, including oxygen,” the coroner found.

“At 2,366 ppm of carbon monoxide, toxicity would be similar to that experienced from a surface exposure of 6-7,000 ppm.”

Expert advice presented to the inquest found that even if Mr Thwaites had been assisted, the extreme levels of toxicity meant his “survival would not have been guaranteed”.

Coroner Clements found that the source of the carbon monoxide contamination in Mr Thwaites’ air tank was from the air compressor used to fill the tanks, operated and maintained by the Underwater Research Group of Queensland Inc.

The air compressor had been noted by club members to be faulty and was not filling tanks fully. It was repaired a few weeks before Mr Thwaites’ fatal dive.

An expert told the inquest old air compressors such as the one operated by the club had a high risk of contamination that could create toxic levels of carbon monoxide.

Significant legislative reforms were needed to regulate the diving industry and improve the maintenance and assessment of air compressors and other diving equipment, the coroner found.

“In conclusion, the most important issue identified following Mr Thwaites’ tragic death was the need for education to alert divers of the risk of contamination when filling their cylinders,” Coroner Clements wrote.

“The risk of carbon monoxide contamination is a lethal risk, and a ‘sniff’ test will do nothing to alert a diver to the odourless gas.

“Divers can improve their own safety by informing themselves of the Australian standard for breathable air.