The man named as Ben Gerring, was in the water near Mandurah, when the attack happened.
Local media suggests that Gerring was resuscitated before he was taken to hospital. He remains in a critical condition.
“He was right out the back looking to get a big wave, one of the set waves that had been coming through during the day,” Brian Williams, president of the Mandurah Boardriders Club told ABC.
“He’d sort of paddled out the back, sort of past the pack slightly. And next thing all hell broke loose and they were trying to bring him in.
“His board was broken in half,” said Williams.
A warning was issued before the attack, after a shark was seen in the local area.
