Adul Sam-on, 14, the only member of the group who speaks English, told reporters he was so stunned when the British divers surfaced that he could only say “hello”.
“It was magical,” he told a packed press conference in Chiang Rai, “I had to think a lot before I could answer their questions.
“It was in the evening when we were scratching rocks on the top of the boulder and we heard voices.”
The boys said they started to feel weak after two days but continued searching for a way out.
Coach Ekkapol Chantawong said: “We had two solutions – wait for the rescuers or try to get out, but we could hear the water rising towards us.
“We took turns digging at the cave walls. We didn’t want to wait around until authorities found us.”
The team had no food with them when they entered the tunnels and survived on water alone, even drinking from the cave walls.
Youngest member Chanin Vibulrungruang, 11, said: “I had no strength. We felt dizzy and hungry while we were trapped in the cave complex. We tried not to think of food because it would make us hungrier.”
The boys, who sported fresh haircuts, have reportedly each gained 6.6lb since they were rescued by a team of expert divers last week.
Wearing their football club’s kit, the group thanked their rescuers and told how they kept their spirits up in the cave by playing draughts and chess with the divers.
In a bittersweet moment, the group also expressed their condolences to the family of Saman Gunan.
The Thai Navy Seal died on July 6 while replenishing oxygen canisters along the route to the cave.
Two of the boys held up a pencil sketch of 38-year-old Mr Gunan, while Chantawong said the group felt they were “the cause of his death”.
He added that they will be temporarily ordained as Buddhist monks in tribute to the diver.
Several of the boys also apologised to their parents for sneaking off to the caves after claiming they were only playing football.
As the boys looked forward to returning to their homes, justice ministry official Tawatchai Thaikaew asked for their privacy to be respected.
He said: “We don’t know what wounds the kids are carrying in their hearts.”