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.
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.
"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."
"The most important thing to have was a full face mask which had been applied inside with positive pressure to enable them to breathe and to be relaxed enough so not to feel any anxiety during the process," he said.
"There was a lot of chaos but we were so task-orientated, focused, and we blanked that out and carried on with the job in hand, step by step, until we achieved success."
"Are we heroes?" he said. "No, we were just using a very unique skill set, which we normally use for our own interests and sometimes we are able to use that and give something back to the community."
Jewell said the diving conditions "were extremely challenging. There was poor visibility and responsibility for another human being's life."
"The Thai authorities took a lot of steps to divert rivers on the mountaintop which we believe bought us as lot of time to get this outcome," he said.
Former Thai Navy SEAL Saman Kunan died during the operation while replenishing oxygen canisters.
British caver Vern Unsworth, 63, who lives in Chiang Rai, was instrumental in linking up the Thai authorities with the British experts. "I was actually scheduled to go into the cave on June 24 anyway," Unsworth told CNN in an interview in Thailand."I got all my gear ready, and I was going in to do a solo trip just to see what the water levels were like. And I got called out at 2 o'clock Sunday morning, and I was there for the whole 17 days."
Unsworth's role in the rescue was also pivotal because of his intimate knowledge of the Tham Luang cave system, which he describes as his "second home" after spending the past six years exploring it.
He had been involved in cave rescue operations in the UK before, but "nothing on this scale."
It was Unsworth who initally pinpointed where he thought the Wild Boars team would be waiting. They were found 200 meters away from that point, which was "probably around about the best place they could have been," he said.
The flooding of the cave could not have been predicted, he said, as the floodwater had come through three to four weeks earlier than last year.
"These kids were just totally unlucky. Wrong place, wrong time," he said. "It happened very quick. You can't blame the coach, you can't blame the kids."
In the early days of the search operation, Unsworth said he quickly realized that outside expertise was required, and advised the Thai authorities to bring in specialist cave divers who had dealt with similar rescues in the past.
"It was a race against time," he said. "They needed world class divers and that's what we got."
He was the first one to suggest calling for help from Volanthen, Stanton and Robert Harper -- who arrived a few days into the search on June 27.
"(They went) straight into the cave," Unsworth said. "That's when things started to really happen."
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Unsworth described how after the euphoria of finding the team, the reality set in of the seemingly impossible task ahead: getting them out of the cave.
"Just getting to the dive start point was proving to be very difficult," he told CNN.
"You get to a stage where only 200 meters into the cave you hit what we call a sump where the water meets the roof," he says. "So that was making it difficult anyway to get into the system, never mind start from the diver point, which was chamber three."
A few days later pumps were brought in to start taking water out of the cave, which along with the low levels of rain that week, helped to lower the water levels as much as possible. But when heavy rains were forecast, the deadline approached for the rescue to begin.
"It got to a point where we knew that the weather forecast wasn't going to be too brilliant," he says. "We said we have to get in."
The complexities of the cave diving and the dangerous route the divers had to take with the boys -- many of whom don't swim -- meant they decided to sedate the boys so they would "stop panicking" during the rescue, Unsworth says.
"It was the only way," he said. "Some of these kids couldn't swim and they'd been put into cold water with wet suits on and full face mask, (which is) alien to them."
He added that this would also reduce long-term psychological damage because they won't remember the actual rescue.
The next challenge, Unsworth said, was coordination between all the different groups including the Thai Navy SEALs and international volunteers.
"They had never been involved in anything like this," he says. "I think it was just communication. It was difficult at times. Sometimes things got misinterpreted."
Unsworth said he expected a "high rate of attrition" in terms of the the boys' survival, but added that hopes increased after the first day of the rescue.
"Sunday was when the first four came out and they were all strong and nothing really to worry about them," he said.
"It gave us hope for the next four and the next five," he says, especially after the "very sad" death of Kunan.
The worsening weather added to the concerns among the rescue teams.
"The last day was the worst day," Unsowrth said. "The third day you have to get five out, plus four Navy SEALs, and the weather is changing quite rapidly. The water levels did come up on the Tuesday. You could see it happening. You could feel the tension."
Chatting to CNN in a leafy café north of Chiang Rai, Unsworth appeared exhausted physically and emotionally, and is still reeling from the outcome of the rescue.
"Just to get any of them out alive would have been a miracle. But to get 13 out of 13 ... won't happen again," he says. "(It's the) biggest miracle ever."