The first movie centered around the thrilled cave rescue of 12 Thai schoolboy footballers and their coach in June last year made its world premiere on Saturday (October 5) and there was one man in the audience for whom the experience proved as thrilling as it was nerve-shredding.

"You can't help but relive the tension and the fear we were feeling, but also there was that sense of excitement and relief when it was all over," rescuer Jim Warny told AFP.

The Ireland-based Belgian was among the crew of international cave rescue divers who plucked the "Wild Boars" and their coach from the Tham Luang Nang Non caves last year and he has traveled to the 24th Busan International Film Festival for the world premiere of the fittingly titled The Cave.

Warny plays himself in the film and said the experience – his first in film – had been therapeutic.

"For me it's not about making a profit it's been about inspiring other people to show that great things can be achieved, against the odds," said Warny. "Physically, I was back at work on Tuesday after I returned on Sunday. But it took six months to come to terms with it and I worked through a lot of it during filming too."

Directed by Irish-Thai film-maker Tom Waller, the film is the first in what is expected to be a rollout of big- and small-screen treatments of the story that gripped the world for the 18 days the group was trapped underground in the virgin cave.

Warny had only just gone back to Ireland, to his partner and his day job as an electrician, when the calls started coming from filmmakers, TV producers and journalists.

"I'd returned home after completing the rescue and the pressure suddenly changed," he said. "It was almost like more pressure than the actual event. But it's worked out OK in the end."

Waller's film puts its focus more on the rescue effort than on the kids and the coach who were trapped – more by necessity than design – after those rescued signed deals tying them to a Netflix series in the works.

Reports say they were paid around 100,000 U.S. dollars each and there is also a National Geographic documentary in the works from the team behind the Oscar-winning film "Free Solo."

"There was a lot of detail of the rescue that the world hadn't really been told about, like the sedation of the kids and the background to the rescuers," said Waller.

"Once I got in touch with Jim and met him all this started to be revealed and I saw how much more there was to the story that hadn't been told. Sure there was the rescue, but how? I wanted to tell the story of the people who weren't on YouTube."

That was impossible in Warny's case because once he came to Thailand he spent much of the time in the cave, under water. He'd come to cave rescue diving after being drawn to the "technicalities of it all."

He started as a support diver but ended up helping guide the sedated boys out, and carrying the coach to safety himself.

"Usually when we get called out it's for body recovery," he said.

"But this time everything worked. It was a surreal experience when we held them. That they were all alive was incredible and a true testament to their bravery. I think it is a story that should just keep being told and this film helps do that."

The Cave is set for release in Thailand on November 28, with further international markets to follow.

(Cover: The portrait of rescue members is seen in the interactive exhibition on the Thai Cave rescue operation at the Siam Paragon shopping mall in Bangkok, Thailand, August 30, 2018. /VCG Photo)