Taking your gear off to get through small passages is standard practice for cave diving, something I did all the time. But I never penetrated farther than a couple hundred yards, and I can’t fathom the skill and knowledge, not to mention the courage it took to pull this off.
The brought food to them that way.
The really frightening part is the boys were terrified of putting their heads underwater. They tried and tried, but there was no way they were going to be able to swim them out.
Not conscious, anyway.
A brave MD came up with a sedation protocol to take them out under general-anasthesia class UNCONSCIOUSNESS.
He would have been destroyed by public opinion if it had failed and even one boy had died.
But they all made it.