Imagine. You're strapped into the driver's seat of a troop carrier being lowered by crane into a lake.
You've been told if things go wrong, you may have to be resuscitated.
Icy cold water starts gushing in at your feet. In seconds it's up to your chest. The shock of the cold takes your breath away, right when you need a lungful of oxygen the most. You manage one more big gasp of air before you're fully submerged.
Now, you must sit tight. Keep your seatbelt on until the scuba diver under there with you gives the signal to get out.
Seconds feel like minutes as you wait for the squeeze on the shoulder.
You need to stay calm. Keep the presence of mind to get your seatbelt off and make sure your clothes or feet don't get caught on anything as you release yourself from the driver's seat and swim out the back window.
It sounds like the stuff of nightmares, but Byron Bay singer songwriter Pete Murray, who recently went through this panic-inducing ordeal in Channel's Seven's reality series, SAS Australia, loved every moment of it.
"It was a real buzz," he says.
"It sounds crazy, but I was actually really relaxed down there."
The 'drowning' challenge wasn't so easy for the other contestants.
Celebrity chef Manu Feildel decided it was all too much and left the series rather than go through with it.
Murray says it was his experience in the ocean that gave him an advantage.
"I surf quite a bit so I'm used to being relaxed under the water if I get hammered on a big wave.
"When you're relaxed you can hold your breath for quite a long time."
"It (the submerged vehicle escape) was my highlight. Exciting and dangerous."
DRAWN TO THE ADVENTURE
Having been a fan of the first season of SAS Australia, in which celebrities face a series of physical and psychological tests under the direction of elite ex-Special Forces soldiers, Murray, 51, says he jumped at the opportunity to be part of the second season.
He joined others including Alicia Molik, Isabelle Cornish, Jana Pittman, Koby Abberton and Mark Phillippoussis.
For a man known for his chilled music - and who has spent the past 16 years living what most would consider the ultimate laidback lifestyle in Byron Bay - joining SAS Australia might seem an unlikely choice, but Murray says he's always enjoyed pushing himself to his limits.
"When I was younger my whole life was sport.
"I used to do athletics and swimming and footy" (his talent in rugby almost saw him enter a career in the sport until a knee injury put an end to that dream).
The adventure of the show appealed too.
"I love the unpredictability of it...flying in helicopters and jumping out of them...that's exciting stuff."
'I HOPE MY BODY HOLDS UP'
Despite his enthusiasm, there was no shying away from the fact that at 51, he would be the oldest male competitor on the show, and this would add an extra level of difficulty.
"I've always kept fit as much as I can, but it does get harder when you're getting older and you've got kids... and just the lack of time you have," he says.
"I've always kept fit as much as I can, but it does get harder when you're getting older and you've got kids... and just the lack of time you have."
He's had two knee reconstructions due to sports injuries and injured himself again while training for the show, which really upped the pain factor and put him on the back foot from the beginning.
"I hadn't run for about 25 years because my knees have been injured through football.
"I went to a gym and jumped on a treadmill and after about a minute I strained my calf. So I was three weeks out from the show and I strained this bloody calf."
During the first helicopter challenge, before the injury had had a chance to fully recover, he re-injured it.
"I smashed my calf on the rail so I was just back to square one.
"So right from the start of the show I was in pain straight away."
Being older than most other contestants also created some self doubt, he says.
"A lot of them are Olympians and good athletes, not far past their prime, so they're really in good condition. So part of me was like - I hope my body holds up.
"And I think the older you are too you kind of have that little bit of doubt about what you might be able to achieve."
"I thought, last time when I was at the play area with my daughter I struggled to get across the play gym thing. I mean how am I going to do this?"
Overall, however, Murray says SAS Australia was 'one of the most thrilling things I have ever experienced' and he wouldn't hesitate to do it again.
"I'd be a bit more prepared for it this time. I loved it, it was exciting and you know, there's nothing that I failed when I was there.
The fourth episode tomorrow night (Monday, September 20) week will shed some more light on why he is so keen to return, he says.
"I won't say much more, but yes I'd love to go back and do it again."
- SAS Australia continues Monday-Wednesday 7.30pm on Channel 7 and 7plus.
In between flying around in helicopters, escaping from submerged vehicles, and welcoming a new baby daughter to the world in June, Murray has managed to find time to write and record some new music.
This week the 17-time ARIA nominated musician, who has sold more than 1.2 million albums in Australia alone, will release the first single from his new EP, Hold Me Steady.
It's a track he says is about someone who you think is awesome - a partner, a child or anyone in your family.
The song was written with UK musicians, the Dunwell Brothers, who also feature on vocals and harmonies.
"They're amazing singers, they did all the harmonies on this and it's just so soulful and rich," Murray says.
"It's a huge chorus, and it's going to be a massive sing along chorus for the live shows."
Those live shows are what Muray hopes will be back in a big way in 2022.
"Next year is going to be a busier year for everyone," he says.
"I just hope the state governments don't close borders.
"It makes it very difficult when so many people rely on crossing their border for their work.
"I just hope they have some common sense now and leave that open and let us be Australia rather than a bunch of states working separately."