The long-term Hunter Westpac rescue helicopter crewman was part of the team that scoured the coast in the hours after Redhead surfer Glen "Lenny" Folkard was attacked by a shark.

The number of predators chasing schools of baitfish was so high that Mr Nickisson and his crew advised local councils to close the beaches from Stockton to Caves Beach.

"To have sharks that close to city beaches, that many and that big, just blew my mind," Mr Nickisson said.

"I have never seen anything like it."

The sightings included a large shark, at least four metres long and possibly a great white, swimming towards a surfer down the beach from where Mr Folkard was surfing.

Mr Nickisson said the shark was heading "straight at him" and was within 20 metres when crewman Heath Aland saw it and the helicopter was able to hover above and warn the surfer.

"We really feared for this bloke's safety – it was dire," he said.

"My heart sank. We thought we were going to witness something really bad.

"This bloke will know who he is but until he reads the paper he won't know how close he was to being in a lot of trouble."

More sweeps of the coastline yesterday morning reported fewer sharks, although a large pack of hammerheads was near Caves Beach.

The shark that attacked Mr Folkard was most likely an adolescent great white shark, Surfwatch Australia director Michael Brown said.

After seeing the photo of Mr Folkard's damaged board, Mr Brown said the shark was probably between 1.5 and 2.1 metres long.

"You rarely hear a report of a fully grown great white attacking a human," Mr Brown said.

Juvenile great whites eat almost exclusively bait fish but adults can prefer seals and whale calves.

"Just like us humans, the adolescents are in a transition phase, they try different things and take risks," Mr Brown said.

"Unfortunately they don't have hands and check things out with their teeth."

Mr Brown said a dedicated aerial baitfish monitoring program would be more effective than shark netting.

He renewed calls for the government to fund a radio frequency on which pilots could report schools of baitfish.

"If a pilot saw a large school of baitfish off Merewether beach heading south they could call it in and the beaches down south could be evacuated."

In October, The Newcastle Herald reported Mr Brown's predictions that shark populations off the Hunter and Central Coast would boom this summer due to nutrient-rich water, plentiful baitfish and warmer ocean currents.

Mr Brown said yesterday that he wasn't surprised when he heard of the Redhead beach attack.

"There are millions and millions of baitfish out there at the moment and the rain and the heavy seas has brought them closer to shore," he said.

The Newcastle Herald