Two cave divers who pulled off the remarkable rescue of 13 people from a flooded cave system in Thailand have been given honorary degrees.

The operation led by John Volanthen, from Bristol, and Rick Stanton, from Coventry, has been described as one of the greatest rescues of all time.

The unlikely heroes were called in by the Thai Government after heavy rain marooned 12 members of a junior football team and their assistant coach in a cave complex in the north of the country.

The rescue involved 5,000 people, with Mr Volanthen and Mr Stanton leading the risky search sorties.

The pair had to navigate 2.5km of constricted underwater passageways, in near zero visibility, against a fast flowing, debris-strewn current.

On July 2, 2018, nine days after the search started, the 12 stranded boys and their coach were found.

But with oxygen in their small air pocket dwindling, and more monsoon rains predicted, time was running out.

Mr Volanthen said: “Having operated in difficult conditions, I was reasonably confident in being able to manage my own safety.

“For the boys it was extremely dangerous. Trying to get them out was something that hadn’t been done before.”

With the help of an anaesthesiologist, each of the boys and their coach was injected with anaesthetic ketamine, the anti-anxiety drug Xanax and atropine, which slows heart rate and reduces salivation.

Over several hours, the unconscious boys were dragged and squeezed out of the submerged cave by Mr Volanthen, Mr Stanton and a team of cave divers.

Despite having little medical training, they had to inject the boys multiple times with the drug mix to keep them sedated throughout the rescue.

Any snag of breathing apparatus could have drowned the unconscious boys and the wrong dose of the drug may have caused them to wake up and panic – or fall asleep forever.

Had something gone wrong, they could have ended up in a Thai court.

Mr Stanton said: “It was unprecedented, nothing really compares. People are citing it as one of the greatest rescues of all time.

“It was a protracted two-and-a-half weeks and you had to think outside the box. We were literally writing the procedures, there was no manual – this had never been done before.”

The pair both received George Medals for the rescue and have now been awarded honorary degrees from the University of Bristol.

Linda Wilson, vice-president of the university’s Spelaeological Society, nominated Mr Volanthen and Mr Stanton for their honorary degrees.

“Rick, John and the other rescue divers were being asked to perform an impossible task,” she said.

“Fortunately, by a combination of extraordinary courage and meticulous planning, they overcame all the odds and succeeded in one of the most extraordinary rescues that has ever been attempted, ultimately bringing out all 12 boys and their coach alive despite the most hazardous conditions imaginable.

“No-one could better exemplify the values this university prizes – resilience, courage and outstanding skills – than Rick and John, who were to save the lives of so many others, whist risking their own lives, daily, for the 15 days of this enormous rescue effort that held the world’s attention.”

The pair plan to go diving together near Bristol the day after the graduation ceremony.