But for Thai cave rescue hero, Dr Richard Harris, the earth’s abysses have become his refuge.

And at times, according to a new feature film Deeper detailing his most dangerous adventure yet, his therapy.

Speaking under the trees and sunshine at Darwin’s Deckchair Cinema, the cave diver and former Darwin resident said he certainly sympathised with those who watched cave diving with horror.

“But it’s become a place of refuge,” Dr Harris said.

“Whatever anxieties I have in my day to day life or fears I have about the dive itself … as soon as I put my head underwater, that all vanishes. I just love it.”

The cave rescue of the Wild Boar Thai soccer team in 2018

An anaesthetist by trade, Dr Harris first rose to worldwide fame for his role in the international efforts to rescue 13 members of the Wild Boar soccer team from a flooded Thai cave in 2018.

When the young players and their coach entered the Tham Luang Nang Non cave in June and were not seen for nine days, a rescue operation launched by the Royal Thai Army found the group trapped inside the complex cave system after it flooded.

As international experts from another 14 countries joined the rescue mission, Dr Harris, who had started running courses on rescuing people trapped in flooded caves, asked if he could help.

However, when he found out the plan to get them out alive would involve anesthetising them he refused, until he realised there was no other option.

“We either leave the boys in there to die, which would take weeks, or we tried this thing, and at the very least, their bodies would be returned to their parents,” said the dad-of-three.

“They would die under the anaesthetic rather than dying of exposure and starvation, lost in the cave.

“I thought of those two choices, I know which one I’d rather if it was my son, so I agreed to do it.”

Before the rescue mission, he and Australian diver and friend Craig Challen navigated 4km of the cave’s system to meet the team.

Despite the boys being in the cave for two weeks, with skin starting to deteriorate and many suffering from chest infections, Dr Harris said they were very positive.

“They were all upright, smiling, talking, mucking around like a bunch of boys on a school camp,” he said.

“I was blown away by the level of courage and confidence and how well they seemed to be after everything they’d been through.

“They were inspiring.”

Deeper: The exploration and obsession with New Zealand’s Pearse Resurgence

The boys and their coach were successfully rescued on July 10 in a moment the rest of the world celebrated.

What followed was a flurry of titles and opportunities for Dr Harris.

In 2019, he was named co-Australian of the Year alongside fellow dive partner Craig Challen, he retired from being a doctor, became a public speaker and was named Lieutenant Governor of South Australia in 2024.

But despite his many accolades, Dr Harris, 61, said secretly he was struggling to feel satisfied.

“For me, I’ve been exploring caves for so long now and I’m never satisfied with however much success I’ve had in that,” he said.

“Deep down, I just wanted to do something that was really new and exciting.”

Even after the cave rescue, Dr Harris still had not found his Everest, until he started exploring a cave in New Zealand called the Pearse Resurgence.

Situated on the South Island in a remote area, it is one of the world’s deepest cave dives and requires a journey by helicopter with all the needed equipment.

After his first couple of trips, Dr Harris said he became obsessed with finding where the source of water was in the cave and it soon became an annual trip to explore but also develop the technology and techniques needed to push deeper.

At well over 240m in depth with water temperatures of six degrees, dives can last up to 16 hours, which means the regular wetsuit and scuba tank does not cut it.

“It’s become a very complex system with huge amount of surface support,” said Dr Harris.

“It’s a long story that I’ve been capturing on film all throughout the process.

“In 2023 we decided we were going to test something new and slightly hazardous in the form of using hydrogen as a breathing gas because some of the physical properties of hydrogen, in theory, would allow us to dive deeper than we were going already and minimise the risks of diving at that depth.”

The approach is not a new one.

As far back as World War II, the US and Swedish navies and the French oil and gas industry have experimented with the gas, but it has not been attempted outside of those arenas.

So armed with his research, courage and a rebreather, Dr Harris and his team attempt to push past these boundaries in the feature film Deeper, even at the risk of his lungs exploding.

“We do a Mount Everest to prove something to ourselves and that’s essentially what this is about,” he added.

“It was a bit of an ordeal.

“Deeper describes the path physically into the cave but also the look into how we manage risk, and why would we take on these unknowns to further both the technology, the opportunities for exploration.

“But it’s also a bit of an inward look to why do people want to risk their life to prove something which probably most of the world couldn’t give a rats about?

“And most of the time I’m thinking about what do I have to do to be satisfied for myself and this is maybe the first time that I’ve actually done something that I’ve been proud enough of to say ‘that’s enough’.”

‘Uncomfortability is how we grow’

Driven by this feeling of achievement and the releasing of Deeper, directed by acclaimed filmmaker Jennifer Peedom, Dr Harris said he had made the conscious decision to step back from any future high-risk trips for the sake of his family.

But he encouraged people, particularly young people, to keep doing things that were uncomfortable and produced risk.

“That’s how you build resilience,” he added.

“Those kids in the cave … they had a life that wasn’t all entirely safe and comfortable and I think those experiences actually made them a lot stronger.

“We’re not letting young people take risks and learn how to manage risks.

“There’s a little lesson there and that’s the way we should grow throughout our lives, just always pushing yourself into that stretch zone and learning what’s safe and what’s not.

“There’s a big part of that message in the film, I hope.”

Deeper premiered at Deckchair Cinema on October 6, with the film opening nationally on October 30.