The mother of an experienced young sailor who died of carbon monoxide poisoning says faster action is needed from governments to prevent someone else suffering the same fate as her son.

Key points: 23-year-old Nicholas Banfield died of carbon monoxide poisoning on board his yacht in 2016

23-year-old Nicholas Banfield died of carbon monoxide poisoning on board his yacht in 2016 The coroner who investigated his death called for governments to look at laws to make carbon monoxide detectors mandatory in boats and caravans

The coroner who investigated his death called for governments to look at laws to make carbon monoxide detectors mandatory in boats and caravans Mr Banfield's parents say their son underestimated how quickly carbon monoxide could kill

Nicholas Banfield started sailing when he was just seven years old and worked as an instructor as a teenager.

"He was a very experienced sailor, he'd sailed to Vanuatu and back and loved the water, he grew up on the water," his father, Rob Banfield, told 7.30.

After growing up in Tasmania, his passion took him to Sydney to work with marine company Noakes.

"He came to Noakes really as a qualified engineer and a qualified naval architect," his boss, well-known sailor Sean Langman, said.

"But he was a very practical, hands-on person. He wasn't ever going to be bound to the office.

"Fundamentally he was always going to work as much as he needed to to go sailing."

A frantic search

Nicholas Banfield had recently sailed to Vanuatu and back. ( Supplied )

One Friday night in July 2016, Nicholas, 23, took his girlfriend out on his yacht on Sydney Harbour.

On Sunday, she called her family confused and unsure where she was.

Police and friends launched a search.

"Basically we just got as many people as we could call who knew something about the harbour and then tried to retrace the steps," Mr Langman said.

"We actually stole fishing boats off people, just put them off their boats. One guy in a fishing boat said, 'I'll take you around'."

The little yacht was eventually found moored off Balmoral Beach, but it was too late for Nicholas Banfield.

"The female was taken to hospital, she was in a pretty serious condition. Very confused and disorientated," Detective Sergeant Michael O'Keefe from the NSW Police Marine Area Command said.

"Why she survived and the male didn't, I can't tell you."

When police found the gas stove in the "on" position, they realised it was carbon monoxide poisoning.

'Something that can happen extremely fast'

Rob and Leanne Banfield say Nicholas loved the water and sailing. ( ABC News: Peter Curtis )

You can't see, smell or taste carbon monoxide, a gas formed from burning fuel.

Generators, boat engines and some cooking appliances and heaters can produce it.

In an enclosed space or with poor airflow, it can kill a person.

While the threat of carbon monoxide poisoning in industrial settings is well known, some experts are concerned the risks in recreational areas have been overlooked.

"[People] go on a boat or a caravan for leisure, they don't expect that anything is going to go wrong," confined space fatalities expert Dr Ciaran MacCarron said.

"A damaged gas line, an exhaust leaking will potentially kill the person.

"It's not in their expectation, they have no need to worry about it because they think the regulator and other people are looking after them, but clearly that's not occurring."

Nicholas Banfield's parents said he was aware of the risk, but likely underestimated how fast it could happen.

"The thing that we didn't understand and that Nicholas didn't understand, and having spoken to other yachties, was the speed with which carbon monoxide can actually lead to disorientation to start with, the incapacity to think things through and then to unconsciousness and then, unfortunately for us, to death," his mother Leanne Banfield said.

"We had some expert medical advice on Nick's passing, the information was that his disorientation would have taken minutes," his father Rob Banfield added.

"So we're not talking about people slowly being disorientated over hours, we're talking about something that can happen extremely fast."

Multiple coroners' calls for mandatory carbon monoxide alarms

The coroner who investigated Nicholas Banfield's death has called for "urgent consideration" of the mandatory introduction of carbon monoxide alarms. ( ABC News: Natalie Whiting )

The coroner who investigated found a carbon monoxide alarm, which is a bit like a smoke alarm and can cost as little as $50, would have saved Nicholas Banfield's life, and she said "urgent reform" in the area is needed.

"Nicholas Banfield was an intelligent and careful sailor with many years of experience," Magistrate Harriet Grahame wrote in her findings, which were delivered in December last year.

"That such a tragedy can befall him, in itself calls for a re-thinking of the regulation of this environment."

The coroner said it was "frustratingly difficult" to find out exactly how many people die each year in Australia from accidental carbon monoxide poisoning, but between 2011 and 2016 there were 15 deaths that were clearly attributed to using gas and solid fuel appliances in confined spaces without adequate ventilation.

She recommended the New South Wales Government urgently consider "legislation to mandate carbon monoxide alarms in all recreational and leisure craft and vehicles with sealable cabins", along with further community education about the dangers.

Just six months before Nicholas Banfield's death, in his home state of Tasmania, two men died onboard a boat on the Derwent River.

The coroner in that case said the deaths were "entirely avoidable" if a CO alarm was installed, and recommended that all boats with enclosed cabins and petrol motors of any type be fitted with a carbon monoxide detector.

In 2013 another coronial inquest warned of the dangers of carbon monoxide poisoning in recreational activities, after three recreational shooters died in a caravan in Tasmania's Central Highlands.

The coroner in that case recommended "urgent consideration in Tasmania of the mandatory installation of CO detection alarms in any residences, boats or caravans where gas appliances are either permanently fixed or where portable gas appliances might likely be used."

That was three years before Nicholas Banfield's death.

"I just think something needs to happen faster," his mother Leanne Banfield said.

"We seem to have had lots of these recommendations being made from the different states. I think something needs to happen."

'Honouring the sacrifice': marine company fitting carbon monoxide alarms

Nicholas Banfield's former boss and friend, Sean Langman, is now installing carbon monoxide alarms on every vessel that comes through the yards at at Noakes. ( ABC News: Natalie Whiting )

Nicholas Banfield's former boss Sean Langman is taking action on the issue.

"Rather than wait for legislation, we made the decision within our organisation that we would fit CO alarms on every single vessel that comes through the yard," he said.

"We made it a mandatory fit, at no cost to the client."

The project has cost his marine company Noakes about $50,000.

Mr Langman said after seeing an "intelligent, experienced" sailor like Nicholas Banfield succumb to carbon monoxide poisoning he knew other people were at risk.

"We see it as honouring the sacrifice, I suppose, that Nick made, and that's the only way that we felt that we could get it across," he said.

Nicholas Banfield's parents have welcomed the response from Noakes and say legislating to make the alarms mandatory makes sense.

"We just hope that might prevent someone else from losing a loved one. Just to give them one more chance," Leanne Banfield said.