The way I understand it the boys are 1/2 mile down and 2 1/2 miles into the cave system. Part of the route out is flooded, the extent dependent on local rainfall. There are 4 separate flooded areas, one of which is so restricted air tanks cannot be worn and have to be removed and dragged. There is also the velocity of the water to be contended with and suspended clay obscuring visibility. There also seems to be a degree of uncertainty as to how severe flooding events are, this impacts the security of the boy's present location. Having found the boys alive and well is fantastic news but there are some difficult decisions ahead before they can be safely extracted. The lack of both diving and swimming experience, poor visibility and constrictions would make the dive option exceedingly dangerous for all involved.
It really is the ultimate nightmare for the kids, their families and those attempting the rescue.
May the rain hold off until they are rescued.