UPDATE 5.10pm: Police have called off a search for a 23-year-old recreational fisherman who has been lost off the north-west coast for two nights.
A weather warning for Perth and the South West has forced search vessels to return to shore.
"I can confirm the search for Sean Coffey off the coast of Leeman has been called off due to current weather conditions," police spokeswoman Susan Usher said.
"Weather permitting tomorrow, one aircraft and one vessel will continue the search."
The weather warning meant that an air search could not be conducted this morning when boats set out to search for Mr Coffey, 23, along the coast.
Hopes are rapidly fading that he will be found alive, after he and two others were knocked by waves off their 5.5m fishing vessel about 3.30pm on Thursday off the coast of Leeman, 270km north of Perth.
His friend Bryce Weppner, also aged 23, was pulled unconscious from the water by rescuers shortly after noon on Friday, but attempts to resuscitate him were unsuccessful and he was declared dead.
Mr Coffey's 49-year-old uncle Kim Thomsen was rescued about half an hour earlier after a Seven News helicopter saw him floating on his back, naked and being circled by a 3.5m hammerhead shark about 20m away.
The news crew alerted rescuers and in the meantime the helicopter flew low to scare the shark away.
Mr Thomsen was flown to Perth and was treated for hypothermia at Royal Perth Hospital. He was discharged from hospital late this morning, according to reports.
It is understood that Mr Thomsen, who is extremely fatigued after his ordeal, wanted to join the search for his nephew. Although doctors had given him the all-clear, he was told he needed to rest.
Yesterday, Water Police and volunteer marine rescue services from around the Leeman area took part in the search operation.
The search focused on an area north of Beagle Island, which is home to the biggest population of Australian sea lions.