Diver Colin admits: I can’t really swim!

THE makers of a big budget film about the 2018 Thai cave rescue faced many challenges — not least building, and then flooding, five underground caverns; and filming in them, often underwater.

But in addition to all the technical issues on Thirteen Lives, there were human ones, too.

Colin Farrell, pictured, who plays British rescue diver John Volanthen, said of the role: ‘It was a joy — apart from how nervous I was beneath water every day, because some of it was terrifying.’ Perhaps because, as he revealed: ‘I can’t really swim.’

He added: ‘ It was as controlled an environment as it could be. But you know, water’s wet; no matter how much control you have or don’t have.’

Meanwhile, British actor Tom Bateman, who plays diver Chris Jewell, suffers from claustrophobia — a fact he hid from Thirteen Lives’s director Ron Howard during auditions; but which understandably came to the fore when filming. Bateman, who plays Poirot’s sidekick Bouc in the Kenneth Branagh films, said: ‘I cannot believe what they [the rescuers] did — and to be a small part of telling their story is a real honour. But my God I was happy to be finished.’

Thirteen Lives will come out in cinemas this month, before airing on Prime Video.

It chronicles the events of the massive rescue effort launched when a junior football team and their coach became trapped in a flooded cave system.

They were found on an elevated rock around 2.5 miles from the cave mouth.

All 12 boys and their coach were eventually rescued after 18 days underground; anaesthetised and then brought out by divers one by one. One rescuer, diver Saman Kunan, died after delivering oxygen cylinders to the group. And another, Beirut Pakbara, died the following year of a blood infection he contracted during the effort.

More than 100 divers took part — and a billion litres of water were pumped out of the caves, which had been inundated by monsoon rains.