Men rescued off WA thank their saviours

Two of the three men who survived 16 hours floating in the waters off Western Australia after their "unsinkable" boat capsized have thanked their rescuers for saving their lives.

Western Australia's Surf Life Saving helicopter and eight vessels scrambled into action on Wednesday morning, after the boat of 79-year-old Dirreck Fayers was reported missing.

Mr Fayers and his two friends, Les Brockway and Tony Solomans, left the Woodman Point jetty just south of Fremantle on Tuesday night, but had not returned by 7am the following day.

Frantic calls to police and marine rescue authorities prompted an immediate search.

Four hours later they were spotted floating in the water, near the appropriately named Stragglers Reef, strapped together with rope but rapidly losing hope.

After a night under observation in hospital, Mr Fayers and Mr Brockway were released, thanking their rescuers.

"The police, the emergency services, the hospitals, the staff - every single one of them have been so good to us, it has been amazing," Mr Fayers said.

"If I caught a lotto win, I would give half to them."

The five-metre-long boat, with two large motors, was bought from South Africa three months ago, with Mr Fayers told it was "unsinkable".

But during the fishing excursion it took in water and flipped over so quickly the group were unable to set off their EPIRB emergency beacon.

Mr Fayers' son Dirk said he realised his father, an experienced recreational fisherman, was in trouble when he found his car and trailer hours after he was supposed to have returned.

He said the men had said after the ordeal that they had been worried about sharks as they drifted more than 10 kilometres from where the boat sank.

"He did mention that it was a worry to the three of them, that they hoped there were no sharks," Mr Fayers told Fairfax radio.

He said instinct prompted the group to rope themselves together.

"They reckoned with the three of them together it would be easier to spot them - it was instinctive, and it did save their lives," Mr Fayers said.