UPDATE: A 50-year-old Ballajura man has survived more than 20 hours stranded at sea by clinging to the bow of his upturned boat.
The man's neighbours raised the alarm this morning after he failed to return from collecting crayfish pots off the Mandurah coast yesterday.
The man left with his dog for a fishing trip around 9am yesterday.
Peel water police Sen. Const. Ian Davison said rescue crews picked up an EPIRB signal, but only after the call from worried neighbours.
The man was located by helicopter about 20km off the Mandurah coast.
His pet rottweiler, which had spent the entire night by his side, died just before rescue crews arrived.
Sen. Const. Davison said the man was "surprisingly fit and well".
He was transferred to Peel Health Campus as a precaution.
"We're not sure at this time how long he was out there but we think the boat possibly sank about 3pm (Tuesday)," Sen. Const. Davison said.
"He is a very reserved man from what I can make of him and he is certainly very stoic.
"For a man who has been through what he has, he was very collected, very calm and I've a lot of admiration for him."
Volunteers from Mandurah Water Rescue Group towed the vessel back to shore.
Sen. Const. Davison said the episode proved how pivotal it was for boats to carry EPIRBs and on-date emergency flares.