Two doctors have volunteered to stay with children trapped in a Thai cave for four months if floodwaters make rescue attempts impossible. A football coach and 12 young players remain trapped in the Tham Luang cave network in the country's north as experts desperately try to come up with a plan to rescue them.
There are fears fresh rainfall over the next few days could add to flooding in the caves - meaning the boys, who cannot swim, may have to wait until the end of monsoon season in October before they can be brought to safety.
If that does happen, two of Thailand's Navy doctors have already volunteered to stay in the underground chamber for as long as it takes in what is being described as a "huge sacrifice".
British volunteer divers John Volanthen and Rick Stanton were among those who struggled through narrow passages and murky waters to search for the boys, who were found starving but unhurt on an elevated rock on Monday.
A first meal of rice and pork - packaged up in sealed portions - is being prepared for the youngsters, who have already been given energy gels and paracetamol.
Seal commander Rear Admiral Arpakorn Yookongkaew said a team of seven, including medics, are with the boys and looking after them after an underground headquarters was set up, stocked with diving equipment, food and medical supplies.
Teams have been pumping 10,000 litres of water out of the caves every hour. But this is only enough to lower the level by 1cm and more rain is forecast, sparking fears it will threaten the air pocket where the team has taken refuge.
One of the rescue options being considered is to teach the youngsters how to dive. But experts have questioned whether they will have the strength or ability to pick up the skills in time.
Interior Minister Anupong Paojinda said the trapped youngsters, who were lost for nine days, may have to negotiate some sections themselves where tunnels are only wide enough for one person to pass through at a time.
"As rain is forecast in the next few days, the evacuation must speed up. Diving gear will be used. If the water rises, the task will be difficult. We must bring the kids out before then," he said, according to the Bangkok Post.
"Diving is not easy. Those who have never done it will find it difficult, because there are narrow passages in the cave. They must be able to use diving gear. If the gear is lost at any moment, it can be dangerous to life."
Chiang Rai provincial Governor Narongsak Osatanakorn said the health of the boys and coach were checked using a field assessment in which red is critical condition, yellow is serious and green is stable.
"We found that most of the boys are in green condition," he said. "Maybe some of the boys have injuries or light injuries and would be categorised as yellow condition. But no one is in red condition."
Rescuers have asked for the donation of 15 small full-face masks, which are easier for beginners because they fully fit around a diver's face while mouthpieces can be knocked out.
Ben Reymenants, a Belgian cave diver who is part of the international team told NBC News' Today that he was "very surprised they are all alive and mentally also healthy".
He added: "They are actually quite responsive but they are very weak and very skinny."
Reymenants said of those trapped in the cave and the rescue mission: "They can't swim, so they definitely can't dive. The easiest [option] would be that they [rescuers] keep pumping the water out of the cave.
"They need another three or four feet so they can float them out with life jackets, but time is not on their side. They're expecting heavy thunderstorms and rain, which might flood the entire cave system, making the rescue impossible at that stage."
If that does happen Reymenants said the boys and the coach could be expected to be in the cave for "up to three-four months". He added, "Two Thai Navy doctors have volunteered to be locked up inside the cave…a huge sacrifice."
Reymenants said rescue teams had to rely on a 30-year-old map made by French speleologists as they picked their way through the caves.
He told Sky News: "That was the only basis we had. It was pure speculation that they could be there in one of these two rooms. One is called Pattaya Beach, and the other is another dry air pocket. It was all speculation and pure luck that they were there."
He had earlier warned the boys could be cut off if the expected rains are severe.
"Time is not on our side - we're expecting heavy rain in three days," he told BBC Newsnight on Monday. "If the cave system [floods] it would make access impossible to the kids."
Edd Sorenson, of International Cave Rescue and Recovery, told BBC News that swimming out of the cave is "extremely dangerous" and it would be safer for the boys to wait because they may panic in the water.
"As long as the kids know we know where they're at, they have food, a way to keep warm, water or filtration systems and light, it would really be the safest to wait it out.
"Taking them in the water would be extremely dangerous for the kids and the coach - but also for the rescuers."
The boys and their 25-year-old coach were found on a mud bank 1.8m above the water level, 4.8km into the 9.6km network of caves.
They had been cut off when a flash flood from sudden heavy rain locked them in, with no shoes and no food and just one torch, which soon ran out.
The pair of British divers who found them were part of an increasingly desperate search mission launched after the group vanished when the caves flooded on June 23.
News of the group all being found alive sparked scenes of jubilation across Thailand, where the public has nervously waited for news of the team's fate as family members held vigils praying for their rescue.
But hopes of a speedy resolution were on a knife-edge today because of the forecast rains.
Reymenants said he agreed with BBC interviewer Emily Maitlis's assertion that the group could be trapped "for weeks to come yet until they are strong enough".
"None of them can swim or dive so that's going to be a real challenge," he added.
Experts have started planning in detail how to extract the group from the place they were found more than a 1.6km underground.