ABALONE diver Darryl Carrison still doesn't understand how diver Peter Clarkson was killed by a shark on February 17, 2011 as he saw Mr Clarkson shelling, not diving that day.
Mr Carrison was fishing about 200 metres away from Howard Rodd and Peter Clarkson on the morning Mr Clarkson was taken by a shark.
He told the inquest into Mr Clarkson's death in Port Lincoln Wednesday the boat he was diving from headed towards a well known abalone spot near Golden Island but noticed Mr Rodd's boat had already arrived there.
Mr Carrison said he began diving about 200 metres away from his vessel and waved to a person on board the other boat, who Mr Carrison identified as Mr Clarkson.
He said he assumed Mr Clarkson was onboard shelling and Mr Rodd was diving at the time, and Mr Clarkson stood up and sent a "big wave over".
"At the time, it was a big happy smiling wave, I just assumed Peter was on the boat and Howard was in the water," he said.
Mr Carrison said they fished near the pair and sometime later he asked sheller Amanda Bichard if they were still there.
He said the pair had left but Ms Bichard had not noticed, which he thought was odd, because he assumed the boat would have to drive past them to avoid leaving the long way around the island.
Mr Carrison said his boat arrived back at the Point Avoid boat launch somewhere between 4.30pm and 5pm and they made their way to Western Abalone Processors to process the day's catch.
Mr Carrison said when he arrived at Western Abalone Processors and heard Mr Clarkson had been taken by a shark, something didn't add up.
"I said to Amanda, how the f*** could've it been Peter, he wasn't diving," Mr Carrison said.
"It just didn't add up, we thought Peter was standing on the boat.
"It was my impression that Peter had been shelling on the day.
"Still even to this day I thought that was the case.
"We said 'what the hell', basically how did this happen?"
Mr Carrison then spoke to Fisheries officers and told them of the location he seen Mr Rodd and Mr Clarkson fishing when he saw them near Golden Island.
When Mr Carrison learned Mr Clarkson and Mr Rodd had moved to fish at Perforated Island, he said to Ms Bichard: "what the hell were they doing out there".
He said he has assumed the pair had moved to the front of Golden Island to fish.
Mr Carrison said he also thought it was strange Mr Clarkson had been diving in shallow water earlier in the day and then moved to deeper water at Perforated Island, the opposite of normal abalone practice where divers begin their day with deeper dives before moving to shallower spots to avoid the bends.
Mr Carrison said he had dived at the abalone spot where Mr Clarkson was taken near Perforated Island, known as The Lumps, in the weeks preceding Mr Clarkson's death, describing it as "spooky".
He said he had never encountered any trouble using a GPS at that spot and was unsure if radio or mobile phones worked because he had not had to use them when he had fished there.
"I'm not aware of any difficulty in that area," he said.
Mr Carrison said in the few times during his time as a diver when his GPS had returned a no fix signal, it would return within 15 minutes.
"It very rarely stays off," he said.
Council assisting the coroner Amy Cacas asked Mr Carrison what he would do if a diver had failed to surface while he was out fishing.
"I would try and call for help on the radio and I would set the EPIRB off as well," he said.
"My first thought would be to wait for help.
"I think it's sensible."
Mr Carrison said this week's inquiry into Mr Clarkson's death would "find out what happened".
"It's amazing something hasn't washed up."