A 35-year-old diver from Broome faces months of reconstructive surgery after a pressurised water jet he was using 40m underwater on the North West Shelf suffered a catastrophic failure and blew a big hole in his arm.
Richard Bradley had been diving off Technip Oceania's Venturer support vessel 148km north of Dampier, where the life of the subsea infrastructure at the Cossack, Wanaea, Lambert and Hermes gas fields is being extended by 15 years.
Saturation diving is highly skilled work requiring divers to live for weeks on the surface in claustrophobic hyperbaric chambers which simulate being underwater.
Inside, they breathe a mix of helium and oxygen, remaining under the same intense pressure as the depths they are working in for the duration of the job, earning up to $3000 a day.
Mr Bradley had been inside the system for 10 days when he descended in a diving bell attached to the main chamber about 4.20pm on March 30.
With colleague Richard Sanderson, he was 40m deep cleaning marine growths off the subsea infrastructure to inspect the condition of welding when the equipment failed.
"I was using a supposedly solid, high-pressure water blaster and 20 minutes into using it, part of the stainless steel gun fell off and I took a hit," he said.
Mr Bradley's arm was ripped apart and the wound was contaminated with debris, seawater and fragments of his hot water suit.
Helped by Mr Sanderson, he dragged himself back to the diving bell along his "umbilical" - the divers' lifeline which supplies breathing gas, hot water and communication facilities.
"The first thing that went through my mind was 'I can't pass out', as one of the chief dangers is getting sucked into the thrusters of the diving boat . . . big propellers that hold the vessel on station," he said.
"But we were at a very shallow depth and that was one of the things that saved me - if we'd been at the bottom, where we were heading, it would be a five-day decompression and I would have had a massive infection."
After returning to the surface chamber, he started emergency decompression at 9pm after stabilising. If he had tried to race to the surface, he probably would have died from "explosive decompression", which was like "shaking a can of Coke" in the bloodstream.
Mr Bradley finally reached the surface at noon on Friday and was taken to Dampier and then on to Karratha Hospital, where he had surgery to clean the wound. He was then flown to Perth, where surgeons opened his arm from his elbow to his wrist to remove more dead, damaged and infected tissue.
Now he faces up to four skin grafts before undergoing rehabilitation and will be off work for at least six months. He stressed his employers had been "fantastic" and would cover his medical costs.
"In 16 years of saturation diving in some of the dirtiest and darkest countries on some of the flimsiest contracts, I have been incredibly fortunate to have an accident with a company that is looking after me," he said.
The National Offshore Petroleum Safety Authority is investigating the incident.
Technip Oceania managing director Frans Roozendaal said the company was co-operating with NOPSA and conducting its own internal investigation.