A man has told of how he narrowly escaped tragic death by swimming for as long as 5.7 kilometers as he ran from a deadly shark.

A spear-fisherman has recounted his terrifying 7.5km swim with a four metre tiger shark following just metres behind.

John Craig was fishing in waters between Denham and Cape Peron off the coast of Western Australia on Friday when his boat drifted away due to mechanical issues, leaving him alone in the water.

Mr Craig said he tried to signal his friend on the boat but his panic and splashing only attracted a sandbar whaler and tiger shark.

'I had been splashing and screaming for some time and 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 on Sunday.

'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.'

When he saw a large sandbar whaler circling, Mr Craig, who moved to Australia from Sunderland in the UK two years ago, said he gave up hoping the boat would return and decided it was time to save himself.

'I watched the tiger shark circle and then suddenly approach me multiple times from different angles. It was definitely trying to work out what I was and whether I could be "on the menu",' he said.

'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 he was four nautical miles, or seven and a half kilometres, from the shore when he made the decision to swim.

'I thought this was it, this is how I'm going to die,' he said.

Although he knew it was a risk, he said it was his best chance of survival.

'The shark would disappear into the gloom then suddenly reappear behind me, just keeping pace with me behind my fins,' he said.

'The shark stopped approaching me and actually started cruising beside me. For about 500 metres the shark swam on the same path as me towards the shore.
'I had to swim constantly looking around from all angles to make sure there wasn't an unwelcome visitor, with my spear gun pointed behind me to stop anything grabbing my fins.'

Mr Craig said he swam for about three hours before he reached the shore.

When he reached dry land, the spear-fisherman said he wanted more than anything to let his wife know he was OK.

'I just thought about my wife and how worried she'd be. I just wanted to tell her I was alive,' he said.

After half an hour of walking Mr Craig said he looked up and saw a search and rescue plane above.

Mr Craig was then picked up by search and rescue boats, and soon after, greeted by his worry-stricken wife.

While the Western Australian spear fisherman said the shark gave him the fright of his life, he said he bore no ill-will for the predator.

'We need them in the oceans. And as much as it was scary at the time, I can only reflect on how beautiful that big female tiger shark was,' he said.

'If the circumstances were different I would have been stoked to have that experience.'

Mr Craig did not want his experience to deter people from visiting Shark Bay to dive and snorkel.

'It is safe and beautiful. I was in the water for over three hours,' he said.

'I want to thank everyone involved in my rescue... I am eternally grateful and I’m sure I’ll be buying beers for years to come.'