A diver who swam a gruelling 7.5km after being stranded at sea has described how he thought he was going to die as a huge 4m tiger shark stalked him off the Gascoyne coast.
Shark Bay man John Craig said he became separated from his vessel on Friday afternoon, between Denham and Cape Peron, due to a "series of unfortunate events" while spearfishing when he got his spear stuck under a rock at the same time his friend in the boat had mechanical difficulties that caused it to drift away.
His friend raised the alarm that Mr Craig was missing just after 4pm, Perth Now reports.
After calling out, splashing and screaming, Mr Craig realised the boat wasn't coming back and that he had an unwelcome visitor.
"My heart rate was sky high. I put my head in the water to check I was in the same place and suddenly saw a huge 4m tiger shark approaching within arm's reach," he said.
"It was easily the biggest tiger shark I've been in the water with and that's saying something having worked as a dive instructor for over 10 years. I quickly turned and saw another large sandbar whaler circling behind me and it was at that point I decided to give up on getting to the boat and save myself.
"I knew immediately that I had to try to calm down in order to survive.
"It (the tiger shark) was definitely trying to work out what I was and whether I could be 'on the menu', but each time it approached I used my spear gun to block its path.
"After about two minutes of this dance I thought 'I have to get out of here' and started swimming for shore."
Mr Craig said getting back to land was "pure endurance", but the shark followed him keeping pace with him behind his fins.
"I have to admit that at this point ... I thought this was it, this is how I'm going to die," he said.
Mr Craig said once he got into a rhythm with his swimming the shark started cruising further behind him.
He said he swam for about three hours, covering four nautical miles, and once he reached the shallows he was aware of the search crews in the area but couldn't get their attention in his camouflage wetsuit.
Incredibly sore, Mr Craig walked for another half hour, but was eventually spotted by a search plane on a remote beach.
"I just thought about my wife and how worried she'd be. I just wanted to tell her I was alive," he said.
Locals, police, Shark Bay marine rescue volunteers and the Department of Fisheries were all involved in the two-and-a-half-hour sea and air search, which ended at 6.30pm on Friday - thankfully just before sunset.
Mr Craig said he wanted to thank everyone involved in his rescue saying he was "eternally grateful". "I'm sure I'll be buying beers for years to come".
Shark Bay Volunteer Marine Rescue commander Greg Ridgley said Mr Craig's presence of mind to save himself in shark-infested waters was incredible.
"I just can't believe anybody could do that," he said.