VETERAN ocean paddler Ken Dinham is thanking his lucky stars – and an eagle-eyed Royal Australian Navy submariner – after he was rescued from turbulent ocean waters 10km off Perth Saturday afternoon.

The 71-year-old was competing in The Doctor, an ocean paddling race from Rottnest Island to Sorrento Surf Life Saving Club, when he was swept off his ski by a 3m cross swell whipped up by wind gusts up to 60km/h.

Camera Icon A Royal Australian Navy (RAN) Collins Class submarine. Credit: Richard Gale

In a cruel twist of fate his leg leash snapped and he watched on helplessly as his craft skipped away over the water carried by the wind.

Mr Dinham, a voluntary aid worker usually based in Vietnam, then tried to deploy the flare carried in his life jacket but was left stranded when he pulled the string and nothing happened.

In more than two decades of ocean paddling Mr Dinham had never had one, let alone both, of his safety mechanisms fail.

“My first thought at that point was, ‘I’m toast’,” he said. “I had been pushed about 500m off the race route by the wind and knew it would be difficult for anyone to spot me in those conditions.”

Buffeted by waves, Mr Dinham began frantically scanning a horizon that bobbed in and out of sight every few seconds.

“I could see the conning tower of a submarine about half a kilometre away and I still had my paddle so I started waving it in that direction in the hope of attracting attention,” he said.

A conning tower is a raised platform that sits on top of the body of a submarine and contains the vessel’s periscope.

“I knew that in a vast body of rough water the chances of being spotted were very, very slim so after a minute or two I gave up (throwing away his paddle) and started swimming towards an oil rig in the opposite direction,” he said.

Camera Icon Ken Dinham with his wife Fran. Credit: Trevor Collens

Ten minutes into his swim, with the ocean sapping the heat and energy from his body with every stroke, Mr Dinham spotted a “huge black object” out of the corner of his eye.

“I stopped and turned around and about 100m away was the fully surfaced submarine,” he said.

“At around the same time a rescue boat pulled up alongside and I heard a voice shouting, ‘You OK there mate?’ I said, ‘No, I’m not actually’.”

After being pulled aboard and wrapped in a thermal blanket Mr Dinham discovered from the crew of the boat that they had been alerted to his plight by the submarine, which had diverted from its course to follow him.

“I couldn’t believe my luck. I just felt incredibly overjoyed and relieved and so grateful to the Australian Navy,” Mr Dinham said.

Waiting back on land, unaware of the details of the incredible rescue, were Mr Dinham’s partner Fran Siversten and his two Fremantle-based sons.

“When he got off the boat I could see he was shaking from the cold but when the story came out I could hardly believe it,” Ms Siversten said. “He is incredibly lucky.”

It is believed the submarine in the rescue was one of six Collins class vessels based at Garden Island.