THE state's worst drowning tragedy in more than 20 years has prompted calls for a major crackdown on rock fishing safety.

Relatives flew from Hong Kong to Sydney yesterday to comfort David Poon and grieve for the loss of his father Po, 63, his mother Delphine, 61, his brother Dillon, 25, and two friends, a 56-year-old man and his partner, 58.

The group had been on their weekly fishing trip to Catherine Hill Bay, south of Newcastle, on Sunday afternoon when they were swept into the water by powerful waves.

Locals Sharon and Andrew Bourke spotted the group walking towards the rock platform from which they went missing.

"We were talking about how big the swell was when we went home and I actually said, 'mark my words, someone would have been washed off the rocks today'," Mrs Bourke said.

"It's weird to think that we saw them walking to their doom."

Mark Kulmar, a wave expert at the State Government's Manly Hydraulics Laboratory, said wave action off the NSW coast on Sunday afternoon was more powerful and dangerous than normal.

Surf Life Saving Central Coast CEO Chad Griffith said rock fishing was overdue for reform.

"We're constantly updating our policies and procedures when it comes to beach safety but when it comes to rock fishing, nothing has ever changed," he said.

He called on the Government to make life jackets compulsory, and to consider other safety measures like harness lines and rock spikes.

David Poon said his family had fished at Catherine Hill Bay "at least 50 or 60 times".

"It's a regular fishing trip - they go up there once a week," Mr Poon said.

Police found one of the bodies on Monday afternoon, and specialist divers located three more bodies in close proximity yesterday morning.

Authorities don't believe the fifth missing person - Mrs Poon - could have survived, but David remained hopeful his mother would be found alive.

Originally published as Calls for tighter rock fishing laws