With oxygen levels in their chamber falling to risky levels and monsoon rains threatening to flood the cave up above the ledge where the boys were sheltering, rescuers decided on the least-worst option of having divers escort them out through the tunnels.
Two of the boys had suspected lung infections but the four boys from the first group rescued were all walking around in hospital.
"We are humbled to have been able to provide our expertise and experience to assist in this worldwide operation led by the Thai government", they said.
But he added rescuers may need more than 20 hours, to replan and replenish oxygen supplies, to be ready to mount the next mission.
Then it will depend on the weather. Authorities have said the mission could take up to four days to complete and heavy rain is forecast in the coming days. "And it is up to the environment".
On Wednesday, Thailand's Prime Minister Prayuth Chan-ocha thanked people involved in the rescue. "We should learn from this experience to prevent it from happening again".
The boys were trapped in the Tham Luan Nang Non cave that became flooded by monsoon rains while they were exploring it after a soccer practice on June 23.
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The conditions in Thailand were "extreme", he said, adding: "If any people could execute this rescue successfully, it was our team of British divers".
"All five will be brought out at the same time today", he said, to cheers from reporters and rescue workers.
"The rescue has been huge", said volunteer helper Somjit Saenset, 56.
"I want him to be healthy and come back to study quickly", Phansa Namyee, classmate of 16-year-old footballer Night said.
It has emerged the rescued boys are being held in confinement over fears they have cave disease, which is caused by breathing in fungus from bat and bird droppings.
Onlookers in Chiang Rai, Thailand, watch and cheer as ambulances transport some of the rescued schoolboys from a cave where they were trapped for two weeks. They are still being quarantined from their parents because of the risk of infection and would likely be kept in hospital for a week to undergo tests, officials said. "To see all that heroic bravery in the cave, and to get all the divers out, it's just such a touching event and so personal to me". This means they will not be able to take up the invitation from Federation Internationale de Football Association to attend the Soccer World Cup final in Moscow.