Returning to the shores of Marmong Point hours after the expensive piece of equipment 'cartwheeled' and 'nose-dived' into the lake on Wednesday morning, the lucky-to-be-alive pilot waded into the water once more.

The Newcastle Herald understands the aircraft, which is believed to be uninsured, cost in the order of $280,000 and had been purchased just a week before it careened into the lake.

Firefighters, HAZMAT crews and police were on standby for hours as they waited for a decision to be made about whether emergency services or the pilot would pull the wreck from the water.

Teralba Fire and Rescue NSW firefighter Murray Wright said attempts to remove the gyrocopter were "a little bit unorthodox" but with a pleasing end result.

"The thing is with incidents like this, obviously we have to make things safe in terms of contaminating the waterway which was done with the booms, and then we have to wait for the owner to decide whether he wants us to recover it or he wants to recover it himself," he said.

"With aircraft and a lifting procedure, anything could go wrong; it could drop, it could move on lifting, if it hits the ground it could spark and next minute we've got an explosion which is potentially gas, 98 fuel or oil.

"That's what we're there for, we protect the people who are lifting it, not necessarily the aircraft itself as it's already compromised, we're there to protect people if it does go up in flames."

A crowd drew to watch as the owner battled the slippery underbelly of the craft to pull it upright, before a crane was called in to lift it out in one piece.

Wilson Lift operations manager Trent Wright was tasked with wading into the water to hook the gyrocopter up.

He said it was the first time in his six years on the job he'd had to pull an aircraft from the water.

"We were told there was a helicopter crash and we'd need to come down here to lift it out of the water," he said.

"It was pretty straight-forward, we take the same care with something like this that we would with something that's totalled, it pretty well is, but yeah.

"It was my call to go in, it was a nice day for a swim."

An eyewitness described the hair-raising moment the gyrocopter 'cartwheeled' through the air before nose-diving into Lake Macquarie.

David Prince and his mate Glen McIlroy had just grabbed a coffee when they saw the gyrocopter, a small rotorcraft which uses an unpowered rotor to take off, coming in to land at Marmong Point.

Intrigued, the two men sat and watched the craft and its two pilots go for a second run, about 200 metres from shore.

"He was in the middle of the lake for probably five minutes, and then decided to take off and he just seemed to be getting up speed, virtually ready to take off, and maybe hit a little wave and then just cartwheeled over, nose-dived," Mr Prince said.

The two men inside the gyrocopter were lucky to be alive, one swimming to a nearby boat for rescue while the other clung to the craft as it was towed to shore.

Mr Prince said a few kayakers also came to the aid of the co-pilots before emergency services arrived on scene.

"It would have given them a good scare going over like that you know, cartwheeling, it wouldn't have been good at all," he said.

"[I] don't know what's left of it, it will be interesting when they pull it out to see what's left of it."

Shortly after the crash, all that was visible above water was an overturned piece of the wreck.

Marmong Point local Liz McCombie was out on her daily walk when she heard sirens ring out across the lake.

"I was walking and I heard sirens, a couple of police ... I thought, 'I hope it's not my house going up in flames'," she said.

"When I came back here there was all this excitement, but this morning I saw this helicopter doing a couple of loops.

"I saw it flying and then it landed with a bit of a splash and then took off again."

Ms McCombie said she was relieved to hear the two pilots were okay, after what could have been a tragic end to a day of flying.

A NSW Police spokesman confirmed both people had been accounted for.

"Police have been told that the marine aircraft was attempting to take off from the lake when it nose-dived into the water, causing the aircraft to roll sideways.

"The two occupants of the gyrocopter boat were assisted out of the aircraft by members of the public before being assessed by NSW Ambulance paramedics.

"No injuries have been reported to police as a result of the incident."

HAZMAT specialists established booms around the gyrocopter to contain any fuel leak. NSW Police took control of the incident and authorities will attempt to determine the cause of the crash.

The Australian Transport Safety Bureau (ATSB) has also been notified.

Did you see the crash? Email news@newcastleherald.com.au