RESCUERS’ CHALLENGES

Twelve boys and their football coach trapped in a flooded Thai cave will have to squeeze through an extremely narrow tunnel in pitch blackness -- the main "crisis" point that looms near the end of their treacherous escape bid. Authorities have highlighted the tiny passageway near T-Junction, or Sam Yak in Thai, as the most dangerous element of the journey for the "Wild Boars" team that began yesterday morning, but there are many other potential pitfalls. Here are some of the challenges that the boys and their coach will face leaving the cave they ventured into on June 23, becoming trapped more than four kilometres (2.4 miles) from the entrance because of monsoon rains.

DIVING ABILITY: The boys, aged from 11 and 16, have no diving experience and some can not even swim. They have received training in recent days in preparation for the extraction effort, but they will have to swim using scuba gear through fast-flowing water in darkness, a challenge for even elite divers.


DURATION, STRENGTH: The journey will be a long one. The rescue mission chief told reporters yesterday that the first boy was not expected to emerge until 9pm. This tallies with previous estimates from officials that it would take the divers five hours to reach the ledge where the team is trapped, and six hours for the journey out. The boys were found dishevelled and weak nine days after they ventured in. Although they have been receiving food and medicine since then, their lack of strength could be a crucial factor in determining their fate.

VISIBILITY, PANIC: The water in the cave is muddy and unclear, with one diver comparing it to a cafe latte. The labyrinth has no outside light. The boys will be helped through the darkness by guiding rope, torches and the escorts. Nevertheless, the poor visibility is one of the factors raising concerns about the boys -- already traumatised after spending so long in the cave and having to swim underwater -- potentially panicking.

BAD WEATHER: The operation was launched after several days of relatively mild weather, as more than 100 million of litres of water were pumped out of the cave. Weather forecasters warned heavy rain was on its way, which could flood the area completely. They said there was a 60-percent chance of moderate to heavy rain on yesterday afternoon, and that heavier rain would continue from Monday to Thursday.