Another crisis point looms.

Heavy rains are causing the waters within the Tham Luang Nang Non cave system to rise, despite the best efforts of engineers to divert flows.

This doesn’t only cause waters to rise. It starts to flow faster. It gets murky. It gets cold.

While this makes the entire trip — where boys are ‘buddied’ with two trained cave divers — all the more difficult.

Especially when they hit the tiny passage near the cave system’s T-junction, known as Sam Yak.

It’s the most dangerous element of the journey.

The boys’ oxygen tank must be taken off their backs. A hose remains tethered between it and the boys’ full-face masks. But it must be carried by one of the divers crawling through the narrow space ahead and behind.

In the cold, black, onrushing water, this will be nerve-racking. Even more so with the fresh rains.

And those that remain behind must wait, not knowing the fate of their friends.

SAM YAK JUNCTION

Each boy will carry an air tank capable of carrying enough air for more than 30 minutes. Fresh oxygen tanks are placed every 25 meters — just in case.

It was these preparations that cost the life of former Thai Navy SEAL diver Saman Gunan last week.

These boys — aged between 11 and 16 — have no diving experience.

Some cannot even swim.

But they have been undergoing a crash-course in recent days. And their instructors are among the best cave-divers in the world.

The challenge, however, remains great. And conditions are getting worse.

The single greatest challenge they face is the incredibly narrow Sam Yak cave junction.

It’s some 1.9km from the ledge the boys have been sheltering upon.

But simply getting there is no easy task.

They must crawl up jagged rock walls on their knees. Then they must clamber down the other side.

Some of the obstacle course must be navigated in the cold black water.

Then — already tested and tired — they must confront Sam Yak.

“The biggest crisis spot for diving is on the left from the T-junction,” Narongsak Osotthanakorn, the rescue mission chief, said.

“There is a tunnel that has a passageway going up and coming down narrowly and you have to turn a bit and it’s very small.”

It’s here the boys must be uncoupled from their oxygen tanks. A length of hose will remained linked to it as a rescue diver wiggles through the gap immediately in front or behind.

It’s a tenuous tether to life.

In the cold, enclosed darkness, the onrushing water will compound any difficulty.

Once through, however, is escape.

The cave widens. The waters subside. The boys can even walk upright part of the distance to the forward operating base — and safety.

A MATTER OF STRENGTH

It may be just 4km — less than an hour’s walk at a very leisurely stroll.

But imagine crossing that distance on your knees, and swimming.

Then add steep climbs and descents.

Then add cold onrushing water.

The boys were found cold, dishevelled and weak after spending nine days cramped on a narrow underground ledge.

Since then they’ve been fed, medically treated — and exercised.

But their condition is likely to be less than idea.

And strength will be vital in the ordeal ahead.

Little wonder the rescue teams allow between four and six hours for each escape.

The boys must be rested every step along the way.

They must be warmed. Re-invigorated. Re-energised.

This is why an Australian medical diver was brought in especially to assess their ability to cope with the ordeal.

Exactly whether or not the first four boys brought out first were among the fittest or weakest is uncertain. There are conflicting reports.

Both choices make sense.

Taking the fit boys would have given rescue divers the best opportunity to learn from their mistakes. Taking the weakest boys would make best use of what strength they had, before matters got any worse.

It’s a call that would have had to be made by rescue diver medics.

Then there’s their state of mind.

According to Associate Professor Sarb Johal, Joint Centre for Disaster Research, Massey University and GNS science, the situation is likely to be fraught with tension.

“Support for each other when they are trapped is also important — but situations may also become fraught when forced to stay together for an extended period of time with so much uncertainty and likely stress,” Dr Johan says. “It’s hard to know how it will play out but critical points may emerge, such as who may be selected to attempt escape first and how those choices are made. There are no easy answers to such dilemmas, and there may be many more to come.”

TERROR IN THE DARK

The cave is pitch black. The water is muddy.

Head lamps are unlikely to illuminate more than a few centimetres in front of each boy’s face.

All they will see is murk, and perhaps a reassuring glimpse of the guide line they are tethered to.

There will be bumps. Scratches. Scrapes.

The water will surge and ebb.

It will be terrifying.

“The mental side of this has to be one of the top considerations,” Andrew Watson, an experienced rescuer of mineworkers, previously told AFP.

“Just one individual panicking can cause a problem,” he said.

It will be just as intense for those remaining on the dark ledge.

Oxygen levels will likely continue to diminish. They could become increasingly reliant on air containers brought by divers.

It will get colder.

If the heavy rains continue, the narrow ledge they are clinging to life upon will become submerged.

Rescue workers have already pumped more than 100 million litres of water out of the cave. But they have little hope to counter fresh flows from monsoonal rains.

The boys and their coach will get wetter.

Eventually, space will run out.

But even before that happens, the bone-numbing heart-stopping chill of hypothermia may set in.

Which is why rescue divers are well aware they are engaged in a race against time.

But they must get it right.

Any sign of panic will startle the boys. They must be carefully, precisely prepared to move along the 4km escape route. Every step of the operation must be perfect.

So far, all has gone well.

At least for the boys that have been brought out.

But it’s not over yet.

WHAT NEXT

The rescue of the first four boys proceeded quicker than expected because water levels in much of the cave were such that they could simply be walked through.

This isn’t likely to remain so.

Heavy rains on Saturday and Sunday are believed to have spurred the rescue effort. So far, it’s not had a dramatic affect.

As the new flows makes their way down, each team of divers and boys will face increasing challenges.

But the same careful preparations must be made.

“Our job is not completely done,” head of the joint command centre co-ordinating the rescue Narongsak Osotthanakorn said before the fifth, sixth, seventh and eighth boys were rescued on Monday night. “We will have to do the next mission as successfully as the one we did today. The rest of the kids are in the same spot.

“Air tanks and systems have to be put in place again. I can’t tell you exact timing of the next operation but I can say it will be more than 10 hours to 20 hours. It will not be more than 20 hours. I have to check all factors are stable. The operation then will be carried out.”

The international team of divers rested before Monday night. They rebuilt their strength.

They’ve already lost one of their number.

“From the perspective of the rescuers, including the divers who have established contact with the trapped boys and coach, it is likely to be a time of mixed emotions,” Dr Johal says. “Joy at being able to find them alive, yet mixed with the reality of the challenge that lies before everyone in trying to extract them to safety. Drawing from the established body of research, it is likely that they and other members of the rescue teams will need care and support for their own wellbeing as this situation unfolds.”

But the divers re-entered the cave system.

Their coach, it has been reported, has already volunteered to be among the last to leave.

But even once back in the sunlight, their ordeal is not over.

RECOVERY

Those that have escaped are receiving specialist attention. The entire eighth floor of a nearby hospital has been sealed off just for their care.

They are being kept in isolation. There is concern that they are susceptible to infection in their weakened state. And they’ve been living in immensely unhygienic conditions for a fortnight.

Each boy has a dedicated medical team awaiting them at the cave entrance. These will assess and accompany their charge to hospital — be it via ambulance or helicopter (a choice made according to need, and weather conditions).

The 12 young boys and their coach must then return to life, as normal.

Dr Johal said this will not be easy.

They’re going through an immensely stressful ordeal of uncertainty.

Especially those that remain behind.

“From the perspective of those boys and their coach, the relief of being found may coexist with the knowledge that they remain stuck and that their future remains uncertain,” Dr Johal says.

“It’s hard to know for certain what they do and do not know about their chances of rescue in the short term, and how they may adapt to trying to deal with the possibility that rising floods waters may be a threat to their ability to survive their ordeal, or that they may remain trapped for weeks or months while people figure out the best plan or action.”

It’s likely the boys will be suffering intense feelings of helplessness, fear, confusion and anxiety. The coach is likely suffering guilt.

“The lack of daylight over this period of time means that they may not only be psychologically disoriented, but that many of their basic physiological functions that depend upon circadian rhythms will be disturbed, such as sleep, hormonal functioning, core temperature, their feeding and drinking, and also how their gastrointestinal systems might be functioning.”

Re-establishing these rhythms will be a top priority for those treating the boys.

@JamieSeidelNews