A St Albans diver has revealed his part in the landmark rescue of a Thai football team ahead of a screening of a documentary about the operation.

'The Rescue' from National Geographic Films tells how 12 members of the Wild Boars junior football team and their coach were saved after floods trapped them in the Tham Luang cave system back in 2018.

The National Geographic film, which has been nominated for this year's BAFTAs, focuses on the tenacity of the divers in their efforts to save the boys, including St Albans old boy Chris Jewell, the British Cave Rescue Council's diving officer.

He spoke to the Herts Ad ahead of the screening to explain his involvement in the operation: "When we were called as an organisation I went out when they needed extra divers. I was one of the lead divers, which meant I was swimming the boys out of the cave.

"I was going into the cave each day, the anaesthetist Dr Richard Harris was anaesthetising the boys and one-by-one we would take them in our arms and swim out of the cave. Think of it as a journey with a series of pit stops, rather than a relay race, we had our colleagues supporting us with fresh supplies, and part of the reason why four boys came out each day is that we had four lead divers who felt they could do the job.

"From starting diving to reaching the boys we were travelling a distance of about a kilometre and a half, 50 per cent of the time you were on the surface of an underground river, the rest of the time you were completely submerged. It would take us maybe an hour and a half to two hours to get into the cave, but it was taking somewhere between two and a half and three hours to get out with the boys. So they were long, tiring days."

This was a remarkable operation which had never been tried before, so what were the risks to the divers and the boys? "There was a small amount of risk to our physical safety, but more than that was the risk to our mental health and the fact that we might have been responsible for a tragedy and have to live with the trauma of losing one of the boys, which would have felt very personal.

"In a situation like this it was unprecedented, there was no guidebook or instruction manual, nobody else had a plan of how to make this work, and we would have faced a lot of fierce criticism for the technique as it hadn't been tried before. A lot of things worked in our favour: the cave was relatively shallow and the water was relatively warm.

"The complexity was created really because the boys were sedated and completely unconscious - they fell asleep in the cave and woke up in hospital - and not being a medical professional I did not appreciate at the time that there were hundreds of different ways it could have gone wrong and the boys had not survived.

"If the water had been colder, if the boys had been bigger or older, all of those things could have conspired against us and the boys might not have woken up once they were put under. They were sedated and then transported through a hazardous environment where there was no medical care and little attention could be given to them if things started to go wrong."

And what does he think of the film? "The directors have done a fantastic job telling the story. They really capture the power and emotion of the moment, they transport you back into those moments in time. It's really engaging, and what's fascinating from my perspective is to see the wider story of all the other people participating.

"I have very strong memories of my involvement, but I saw that through the lens of a single diver, whereas there were hundreds of people participating and it's quite fascinating to see all the other things that were going on as we were involved in the diving."

You can see The Rescue at Fowden Conference Centre, Rothamsted Research, on April 1. Doors open 7pm. Tickets are £10 in advance or £12.50 on the door, with proceeds in aid of Macmillan Cancer Support. Book in advance now at harpmaccommittee@gmail.com