Apparently the folks on scene regard diving the group out as the most dangerous option. the safest option apparently is to lower water levels, either by pumping or the end of the rainy season, so that they can walk and/or float out..
Everything depends upon the local conditions - are there narrow bits where only one can squeeze through, perhaps towing your tank behind or below you? how swift is the current? How contorted are the passages/ - they are not necessarily nice straight tunnels.
One key element is buoyancy control - keeping one's self neutral in the water, neither rising nor falling. Bumping into the passage can release cloudy sediments and damage gear. This is something that is often quite difficult for divers to learn in swimming pool conditions with no hazards and is trickiest at relatively shallow depths. Altitude is also a complicating factor.
Diving in restricted overhead situations (typically cave or wreck diving) means that your life expectancy can be easily calculated. There is a finite amount of air in your tank and when you exhaust that, you are done. Panic and inexperience result in greater air consumption, while youth and small size decrease it.
Situations arise in cave diving (equipment problems, lose your mask or regulator, etc) where you are essentially on your own, even with a dive buddy, and it doesn't matter who is behind or ahead of you - you are on your own.
Since this is a marooned soccer team, they are probably interested in the World Cup matches, even while they are they are at the center of World Cup class rescue efforts.
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Geezer in Chief