Police have called off a marine search for 23-year-old international student Heng Yi Goh, who was swept off rocks near Yallingup earlier this week.
Police said Mr Goh, a University of Western Australia student, was standing on rocks at the Injidup Nature Spa when a wave knocked him into the ocean on Monday.
They described Mr Goh's futile attempts to scramble back to safety before being struck down by a second big wave and disappearing from sight.
"He was swept off by a wave, managed to scramble back on a rock, and then was hit again by another wave and wasn't seen since," said Sergeant Jane Gillham, officer-in-charge at Dunsborough Police Station.
"After the first wave hit him he slid back off the rock, then climbed back up again and then got hit by a second wave.
"It's quite steep, it would be a couple of metres to the water level from where he was standing."
The search was called off late on Friday afternoon pending new information.
Photo trip goes horribly wrong
Mr Goh, a Singaporean national studying a Masters of Economics in Australia, was with five friends who are also international students taking photos of the waves when he was swept away.
"My understanding is he was with the group and they were taking photos of the waves, and I guess underestimated the power of the surf that comes in there," Sergeant Gillham said.
A search began on Monday evening but police and the rescue helicopter failed to locate Mr Goh.
The search resumed but conditions were hazardous with four-metre swells and wind gusts at 50 kilometres per hour.
The south-west coastline is notorious for dangerous surf conditions.
In April, one fisherman died and a second was taken to hospital when they were knocked off rocks near Margaret River, about 50km south of Yallingup.
In 2016, a 25-year-old South West man died after jumping from rocks in the same area.
Police said the swell was about six metres when Mr Goh was swept away and conditions had been so dangerous the search boat had to be stood down.
Mr Goh's family in Singapore were notified earlier this week and is attempting to arrange to travel to Australia.
