MAE SAI, Thailand — Worried that heavy monsoon rain could soon make the job even more difficult, Thai officials said Saturday that they might have to quickly rescue 12 boys and their soccer coach from a partly flooded cave by helping them make risky dives to safety.
The boys, 11 to 16 years old, and their 25-year-old coach have been trapped for two weeks — since June 23, when they went exploring in northern Thailand’s Tham Luang Nang Non cave after a practice game. Monsoon flooding cut off their escape and prevented rescuers from finding them for almost 10 days.
The only way to reach them was by navigating dark and tight passageways filled with muddy water and strong currents, as well as oxygen-depleted air.
Getting out via the same route looks like the only feasible option, but a high-risk one, Thai officials say. Cave rescue experts consider an underwater escape a last resort, especially with people untrained in diving, as the boys are.
The path out is considered especially complicated because of twists and turns in narrow flooded passages.
The local governor supervising the rescue mission said Saturday that mild weather and falling water levels over the last few days had created appropriate conditions for an underwater evacuation, but that the conditions won’t last if it rains again.
Thai officials are stressing that they may have to act very soon — meaning within the next couple of days. If weather forecasts are correct, access to the cave could soon close again because of flooding from seasonal monsoon rains.
Earlier efforts to pump out water from the cave have been set back every time there has been a heavy downpour.
Chiang Rai acting Governor Narongsak Osatanakorn said authorities were waiting for two big groups of volunteer foreign divers to arrive this weekend, after which they will be ready to act quickly to bring the team members out when the conditions are right.
Narongsak said experts told him flooding from new rain could shrink the unflooded space where the boys are sheltering to just 108 square feet.
The boys sounded calm and reassuring in handwritten notes to their families that were made public Saturday. Divers made an 11-hour, back-and-forth journey to act as postmen.
One of the boys, identified as Tun, wrote: ‘‘Mom and Dad, please don’t worry, I am fine. I’ve told Yod to get ready to take me out for fried chicken. With love.’’
‘‘Don’t be worried, I miss everyone. Grandpa, Uncle, Mom, Dad, and siblings, I love you all. I'm happy being here inside, the navy SEALS have taken good care. Love you all,” Mick wrote.
‘‘Night loves Dad and Mom and brother, don’t worry about me. Night loves you all,’’ wrote Night, in the Thai manner of referring to oneself in the third person.
The most touching note came from one whose name was not clear: ‘‘I’m doing fine, but the air is a little cold, but don’t worry. Although, don’t forget to set up my birthday party.’’
Another, of indistinct origin, asked their teacher not to give them a lot of homework.
In a letter of his own, the coach, Ekapol Chanthawong, apologized to the boys’ parents for the ordeal.
An update Saturday from the Thai navy said three navy SEALs were with the boys and their coach, one a doctor. The 13 are having health evaluations and rehabilitation, and are being taught diving skills.
Food, electrolyte drinks, drinking water, medicine, and oxygen canisters have been delivered to them. A major concern of the rescuers is that oxygen levels in their safe space could fall dangerously low.
Rescuers have been unable to extend a hose pumping oxygen all the way to where the boys are, but they have brought them some oxygen tanks.
The death on Friday of a former Thai navy SEAL, Saman Gunan, underscored the risks of making the underwater journey. The diver, the first fatality of the rescue effort, was working in a volunteer capacity and died on a mission to place oxygen canisters along the route to where the boys and others are sheltered.