The failure of the pumps happened just after 10pm, about three hours after the coach had been rescued from the cave and the drama shows how rescue workers were racing against time and weather to complete the rescue. Dr Richard Harris, right, with his dive partner Craig Challen. Credit:DFAT The Australian police divers involved in the perilous rescue mission in north-western Thailand have shared incredible new details about the final moments in the cave, the dangerous conditions the men were working in and what it felt like to be involved in such an extraordinary international rescue effort which saved all 12 boys and their coach. Hero Australian doctor The mystery Australian dive buddy of the hero Australian doctor, Richard Harris, who gave final medical approval before each boy attempted to exit the cave with Thai Navy SEALs and the all-star international dive team, was Craig Challen, from Perth, a close friend whom Dr Harris asked to join him on the mission in Thailand.

Dr Harris and his dive partner Craig Challen, and the team of doctors he worked with and DFAT officers. Credit:DFAT It can now be revealed that both men - not just Dr Harris - swam all the way to the boys on each of the three rescue mission days and did not leave the cave until after the boys had been evacuated to safety. Fairfax Media spoke briefly to Dr Harris on Wednesday morning but he declined to comment. He did, however, acknowledge the huge outpouring of support and thanks that had come from Australia and around the world for his efforts. It later emerged that his father died on Tuesday evening. Craig Challen (second from left), Dr Richard Harris (centre) with DFAT staff at his hotel on Wednesday. Credit:James Massola

According to the South Australian Ambulance Service, his father died "a short time after the successful rescue operation in Thailand". Treacherous conditions For the first few days, the Australian Federal Police divers involved in the operation had to dive for sections of the journey through the cave to chamber three, which had become the main operating base for the teams swimming and diving through to the trapped boys. Loading Replay Replay video Play video Play video Approaching chamber three in those first few days, the divers would walk about 300 metres and then have to dive for between 10 and 20 metres. This pattern would be repeated several times.

Those dives to chamber three "might be 10 metres", one of the divers said. "Then you get up and walk, carrying 46 kilograms of diving equipment on your back." The approach to chamber three was probably the most technically challenging point. Loading "[There] was a small hole less than a metre. So you're climbing down through the hole to get into the water." Diving through and on into chamber three was "like diving in sumps, like the S-bend on your toilet. That's what it's like", the diver said.

"There's a big section after the first dives where it's more of a tunnel formed, rocks fallen on other rocks." The Australians' job was to move huge amounts of equipment into the third chamber, including hundreds of air cylinders, to support those who were diving all the way through to the boys. Loading The Australians, who usually perform black-water search operations, were unable to go beyond chamber three as they were held back by their equipment, which would get stuck in even narrower spaces. "More technical divers and cave divers use rebreathers, which is a technical package, or side mounts [oxygen tanks]," the diver said.

At times, the boys were dragged on "skeds", or stretchers, through sections of the cave, but sometimes they had to dive. Once the boys had reached chamber three, more than 150 people inside the cave - Thais, Australians, Americans, Chinese and more - helped pass them, on stretchers, hand-by-hand out of the cave. Loading From chamber three to the exit, a distance of about 1.5 kilometres, people "literally formed a line, passing them hand to hand", one of the divers said. "We were checking as they passed to make sure their air gauges were still full," another diver said, adding they still had their dive cylinders on, as well as full face masks.

That's because, after more than two weeks, air quality in the cave had declined so much. "There was a high concentration of oxygen in the air [cylinders] so we kept the air on." At first, it had taken four to five hours to get through to chamber three because of the need to dive at least three times and because of the more difficult, watery conditions. But, by the end of the mission, as the water had decreased in the cave and as stairs were cut into mud banks and paths were formed beneath guide ropes attached to the walls, the walk took about 40 minutes. The moment the final Navy SEAL, who had stayed with the boys, emerged was electric.

A huge roar began deep in the cave and reverberated down to the entrance as it dawned on more and more of the rescue workers, closer and closer to the cave exit, that their mission was complete. "I was right down the bottom but you could hear all the cheers," one of the divers said. "It was like a Mexican wave when we got the last diver out, that's when the cheers and shouting happened." Late on Tuesday night, the Australian team spoke via Skype for 10 minutes to Prime Minister Malcolm Turnbull, who congratulated them on their successful mission. Asked to reflect on what participating in the rescue mission meant, one of the federal police divers put it like this: "In a lot of ways this will be the most amazing thing. It's one of those career defining moments. I'm actually hoping I don't have another defining moment!"