A Perth fisherman left to the mercy of the ocean says he didn’t want to succumb to the deep blue after his boat flipped off the coast of Ocean Reef yesterday.

Lindsay Lankester was thrown into the water after his vessel was flipped by a freak wave just after 5pm.

Four kilometres from land, he was forced to cling to what little of his overturned boat remained above the surface.

“Thoughts were running through my head like ‘I don't want to die out here’,” he said.

Mr Lankester had a GPS-enabled EPIRB — but it wasn't easy to get to.

If being thrown into the water wasn’t dramatic enough, the 45-year-old then had to dive under the sinking vessel to release it.

He tried four times before started to panic. But on the fifth go he got it.

“That GPS saved my life.”

Mr Lankester crawled back on top of the boat to trigger the life-saving device about 10.30pm.

He was found an hour and a half later.

With the GPS feature on Mr Lankester’s EPIRB police were able to hone in on his location to within 100m.

Without that GPS feature, they would have been searching a five kilometre radius.

“It could have been a lot worse,” Mr Lankester said.

“That GPS saved my life.”

Dramatic vision of the late-night rescue, after Mr Lankester had drifted for six hours, was released by WA Police on Monday.

The PolAir helicopter located the man waving while sitting on top of the bow section of his upturned boat and a water police vessel arrived shortly after to take him into shore.

Mr Lankester was taken to Joondalup Health Campus for treatment for cuts and abrasions and exposure.

A volunteer marine rescue boat recovered the stricken vessel.

A police spokesperson said the incident highlighted the value of having a registered GPS-enabled EPIRB.