Chiang Rai, Thailand CNN  — 

A British diver who first discovered 12 schoolboys and their coach stranded on a ledge in a flooded cave in Chiang Rai, in northern Thailand, has described the moment he first saw them – and played down suggestions he was a hero.

Retired fireman Rick Stanton and fellow diver John Volanthen found the children deep within the cave nine days after they went missing.

Stanton was speaking at a news conference at Heathrow Airport outside London Friday, alongside fellow British divers Josh Bratchley, Chris Jewell and Connor Roe, Irish diver Jim Warny and cave rescuers Mike Clayton and Gary Mitchell.

Divers and rescuers from the Thai cave mission arrive at Heathrow Airport Friday. From left to right: Chris Jewell, Mike Clayton, Rick Stanton, Lance-corporal Connor Roe, Josh Bratchley, Gary Mitchell and Jim Warny

When asked how they felt when they discovered the young football team alive in the Tham Luang cave complex, Stanton replied: “Initially, of course, excitement, relief that they were still alive. As they were coming down the slope, we were counting them until we got to 13. Unbelievable,” he said.

Richard Stanton, left, and John Volanthen arrive in Mae Sai, Chiang Rai province, in northern Thailand, Tuesday, July 3.

“We gave them a little bit of extra light, they still had light, they looked in good health. Then, of course, when we departed, all we could think about was how we were going to get them out. So there was relief, tempered with uncertainty.”

He declined to go into detail about how his team rescued the children, saying it was “too detailed for this point in time.”