As The Rescue documentary hits UK cinemas this week with special nationwide previews screening on 26 October, Natalie Berry reviews this National Geographic take on a story that had the world on the edge of their seats...

When twelve schoolboys and their football coach became stranded in a flooded Tham Luang Nang Non cave in Chiang Rai Province, Thailand in 2018, distraught parents and those following the drama across the world hoped for a miracle. The Rescue by Oscar-winning Free Solo directors Elizabeth Chai Vasarhelyi and Jimmy Chin is a compelling account of the 16-day ordeal endured and ultimately survived by the boys, with never-before-seen footage and gripping reenactments.

At the heart of the international rescue effort was a motley crew of elite British cave divers with the specialist skills and equipment required to reach and rescue the boys. "These are the best cave divers in the world," Thailand-based British cave explorer Vern Unsworth assured the Interior Minister as he handed him a scrap of paper with scribbled names.

The six specialist spelunkers were flown out in business class and treated like VIPs before their work had even started. On arrival at the cave, the team joined an army of Thai and international military personnel, medics and volunteers - an estimated 10,000 people overall - to assess the situation and discuss the options for rescue.

Could the boys wait it out until the end of the monsoon season, if supplied with food and water by divers? Could the group be taught to dive and be guided out? Could an alternative route be bored through the karst limestone? As oxygen levels dwindled and with more rain forecast, time was of the essence. Ultimately, the experts plumped for a risky solution to sedate the boys and dive with them as their "precious cargo". 

There are many similarities between climbing and caving, despite their perhaps more immediate differences. Both involve exploration up, down or along geological features, excessive technical equipment, copious ropework geekery, sturdy risk management and a steady nerve. Where the two pursuits differ is, of course, in their situations above and below ground; climbers seek some level of exposure above a void, while cavers deprive themselves of air, space, dry clothing, comfort and - to outsiders at least - any form of enjoyment by squeezing through narrow gaps. To the uninitiated, caving is surely the epitome of 'Type 2 fun'. 

"You can look at a cave in two ways," diver John Volanthen explains in the film. "You can say 'I'm under hundreds of feet and tons and tons of rock — my life's in danger.' Or you can say, 'My world is this small passage. Actually, it's OK'."

There is plenty of disorienting footage featuring body-width passages filled with murky water in the film, most of which has been reconstructed to tell the story. For a claustrophobic viewer, this could create a sudden urge for wide, open spaces and fresh air. Despite this potential discomfort, the skilful interweaving of archive shots with pick-ups emphasises the danger and commitment of the undertaking, adding to the viewer's respect for the rescuers.

With such incidents earning widespread, rolling coverage in global news, it's easy to dismiss a disaster blockbuster due to 'knowing the story' or fearing over-dramatisation. The Rescue strikes a fine balance between gripping actuality and detailed retelling of events alongside informative graphics. There are also multiple fortuitous coincidences that affect people involved in the rescue, which add further layers of emotion to a story with numerous peaks and troughs (or should that be cupolas and sumps...?)

"I think I hold great pride in what we did," says diver Rick Stanton towards the end of the film. "You could say it's justification for the dedication I put forward into a ridiculous minority sport that no one ever took seriously."

Cave diving and the risks involved don't make attractive suitors of its participants. Stanton describes rescuing dead bodies numbering in "double figures". Having sacrificed relationships and social connections in pursuit of cave diving explorations, rescuer Chris Jewell saw an unexpected upside to the cool-headed focus fostered throughout the many years of practising his hobby.

"I did used to worry that I was a bit too cold, that I was a bit too unemotional," he says. "I found a use and a purpose to that level of detachment. You can use it to do good things."

In a similar vein to Free Solo, The Rescue tells the story of a bunch of unlikely heroes whose single-minded obsession and skill brought them both global accolades and deeper human connections, thrusting them out of the obscurity and darkness of their pastime and into the limelight — albeit covered in mud and looking less-than-glamorous. Should this film also win an Oscar, here's hoping they scrub up well.