Suffering from hypothermia and unable to feel his feet, stricken sailor Geoff Hunter says he was unsure how much he had left in him when he finally dragged his way on to a rocky Bunbury groyne after a 2km swim.
The 62-year-old was knocked overboard as he sailed towards Bunbury harbour on May 11.
A swell hit his yacht in the seconds he was unclipped from his safety line.
With his 8m vessel drifting away from him out to sea, un- injured and wearing a life jacket, he felt his best option was to swim to shore.
Recovering in hospital from the three-hour ordeal, the grandfather admitted he had not been confident he could swim that far but did not have much choice.
"I knew I was in strife but you just have a go, what else do you do," he said.
He said he did not want to waste energy trying and, potentially failing, to reach the boat.
Mr Hunter did not think about the danger he was in and instead focused on swimming.
The most perilous time was when he reached the groyne.
"Twice I got smashed against the rocks . . . which bruised my chest and arms," he said.
"I couldn't feel my feet or hands by then because it was pretty cold.
"I managed somehow to get one leg to push myself up on to the next rock and then another wave smashed on to me but I managed to hang on."
Mr Hunter crawled up the jagged boulders out of reach of the crashing waves.
But his ordeal was not over.
He scrambled under at least two fences but could not get past a wire fence near the Bunbury sea rescue base.
Fortunately, he saw a family fishing and knew he had reached help.
"I had blood all over the joint . . . I was cold and pretty worn out," he said. "I remember their daughter saying, 'Dad, there's a castaway'."
Mr Hunter believes his lifejacket saved him in the water and gave him some protective padding when he was thrown on to the rocks. He hoped his ordeal would remind boaties to wear a lifejacket the entire time they were on the water - saying it was too late to try to grab one during an emergency.
The grandfather, who has now been released from hospital, thanked everyone who helped him - the fishing family and a dive shop owner, who both gave him blankets and called for help, the volunteer paramedics, sea rescue crews who retrieved his yacht and hospital staff.
The incident has not dampened the experienced sailor's enthusiasm for his new S80 yacht, but smiling wryly at his daughter, he admitted he might not sail alone so often.