The devastated father of Hunter Valley bus crash victim Zachary Bray has shared the heartbreaking moment he realised his 'hero' son had died.  

Adam Bray drove three hours from NSW's Southern Highlands to the crash site near Greta after he was unable to locate his son, 29, at any of the hospitals nearby. 

'I'm banging the car door, I'm trying to focus, I'm calling out to him ...

so my focus is on Zach,' Mr Bray recalled of the morning of June 11.

'When I arrived at the crash I was told to wait for news at a nearby cafe, I absolutely wasn't going to do that.' 

Mr Bray told

'I just said, "my son's on that bus", and they said to me, "if your son is on that bus, honestly you don't want to see him".'

'I just sat on the ground, on my own, and broke down, for an hour.'

Zach had attended the wedding at Wandin Estate Winery as a friend of both bride and groom Madeleine Edsell and Mitchell Gaffney and was mates with most of the passengers on board the privately chartered bus. 

He was one of ten people who lost their lives when the coach that was transporting wedding guests crashed and flipped at a roundabout near the Hunter Expressway off-ramp at Greta.

Mr Bray was joined by friends and family at North Curl Curl Beach on Sydney's northern beaches to take part in a memorial paddle for his son on Saturday.

'I never thought that I'd be sitting in the circle with all his mates and my mates,' he said while struggling to hold back tears. 

'He would have been deeply, deeply moved. It's overwhelming, it's really incredible. I don't think I could have got through that without that [support].'

'He's a true fighter ... it's been a transition from me being his hero to him being my hero,' the proud father added. 

'It's a shock that I'm never going to get over, that his mum's never going to get over.'

'I do want justice.'

Andrew Varasadi, Mr Bray's stepfather, awoke to his wife's screams as she read a headline about the horror crash the morning after the wedding.

He frantically rang his stepson before checking the location of his phone - which revealed the device was at a roundabout in Greta. 

'(It) sounds weird to hope that your son's in ICU but that's what we were hoping for,' Mr Varasdi told 7News.

'But then we found out he wasn't in ICU, so there was only one option left.'

His uncle, Haydon Bray, said it was 'beyond belief' that he had died this way.

'He fought and fought and fought and went through some horrible times to come out the other end,' he said.

'(It's) beyond belief. Brutal.'

The 29-year-old had recently overcome a battle with bowel cancer and is being remembered as a hero who had dreams of becoming a fighter jet pilot. 

The driver of the bus, Brett Andrew Button, 58, appeared in court on Tuesday where he remained silent during the entirety of his bail application.

He has been charged with 10 counts of dangerous driving causing death. 

Mr Bray's Singleton Roosters teammates paid tribute to the keen AFL player and other club members lost in the crash with a community run on Saturday. 

Many local players wore armbands during their games to honour the 10 victims.