Basic Cave Diving: A Blueprint for Survival (1986) [pdf]
nsscds.org
nsscds.org
The Thai rescue will use some of these techniques but it's whole different set of challenges they have to deal with; being in a silt out with an untrained person who hasn't eaten or slept much for almost two weeks
Sadly Exley died a few years later trying to get into the record books for "deepest cave dive" which goes again "Going too deep"
Lost in the dark and running low on air, they would claw at the limestone ceilings of the tunnels they were trapped in until the flesh of their fingers was worn away. Even then they’d keep scratching with their exposed bones.
Never developed an interest in cave diving, myself.
From the surface, it's easy to say just follow the guide cables the divers have no doubt installed. Doing that in person is quite different.
The other issue is these are some calorie deprived kids probably not in shape for an extended workout. Maintaining body heat and fighting a not-particularly strong current for 10 hours is taxing for very physically fit people who haven't been food deprived. And who aren't scared out of their minds and burning through oxygen.
For some reason reading this made me shiver in fear. I don't usually visualize scary stuff when I read it, but this did it. I know I would be scared to death if it were to happen to me.
...the trick is what happens when you don't have the guideline in your hand, or something goes wrong with your equipment, or someone's tanks run out, or a diver gets lost, etc. But you train for that, too.
Someone asked my cave instructor, if you lose the line how long should you search for it? The rest of your life, he replied.
you could pass along the cable holding the carabiner in one hand, not slowing you down
Also I read an accident report of some divers who survived a silt out condition, they spent a lot of time carefully figuring out what direction they should follow the rope out to exit the cave in places where it has been wrapped around a stone a few times to anchor it.
There's an overview of various line markers at https://www.tdisdi.com/cave-diving-directional-and-non-direc..., and a great photo of line arrows and a gold line / jump reel connection on Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Line_arrow.jpg
The trick is, the permanent arrows indicate the closest "exit" to the system, so if there's a 1000m cave connecting two freshwater springs, then at the 500m mark you would usually encounter two back-to-back arrows, one pointing to each exit. The trick is, if you haven't personally explored both exits, you can't be certain that they're both navigable. So if you're 750m into that system, lose visibility, and need to get out by feel, you have to find the nearest arrow and then blindly swim in the opposite direction from what it says is the exit. It's... "fun."
Also recently on HN, "British divers at heart of Thai cave rescue among best in world": https://news.ycombinator.com/item?id=17448311 (the British divers in the Thai cave rescue also attempted a recovery in the accident for Diving into the Unknown, and stopped because it was too difficult.)
You have the personnel, who speak different languages, and of variable ability.
There are tasks to accomplish such as laying supply lines, placing cylinders, finding the boys, accompanying lesser trained divers.
There are supplies to manage, food, water, equipment.
I suppose armed forces specialize in planning these types of operations. Most other project managers have more of a luxury of time. I just am amazed about how they put this together. I hope they put together a report afterwards, because people need to learn an awful lot from this.
https://www.theguardian.com/world/2018/jul/06/former-thai-na...
Of course, the most dangerous person is someone who thinks they know what they are doing.
While there may have been other reasons not to send a military presence to assist (I recall it being a rather messy situation as it was), it seems clear we know exactly where the expertise is here, and don't let silly 'special forces' bravado get in the way of getting the job done.
Is there any sedative available which calms you down without also reducing your cognitive/motor capabilities?
EDIT: "Mr [Peter] Dennis also said he thought the boys would have been lightly sedated by a doctor who joined them in the chamber, to prevent them from panicking during the journey out." From the BBC live reporting webpage.
Panicking is almost the worst thing that could happen here. Someone flailing around is a threat to their own apparatus, their rescuer's apparatus, and at best depletes their own oxygen much faster.
It sounds incredibly cruel, but I'd completely understand if they opted for a doped deadweight. I'd also completely understand if they didn't advertise such details until they're certain it was successful. Having the whole world watching adds some political tightropes.
It reminds me a lot about how methodical planning and preparation can help prepare for a better outcome, especially when problems occur. Particularly, the part of how they practice buddy breathing and hand signal communication before going into the real depths reminds me of the proverbial testing before you are ready to "go live in production" (without life/death consequences, just 'revenue' of course). I won't belabor the metaphor but there is something that can be learned from those who go into some of the riskiest situations that a person can put themselves into precisely by "de-risking" as much as possible. For example, the probability of all three lights failing is a fraction of a percent. In a non-silt situation, having a light fail is equivalent to becoming blind.
If you are like me, this X-Ray Mag site below is a fascinating armchair way to read about the small world of cave divers. I know that the closest I will ever get to cave diving is with a full-immersive VR experience when the great, great grand-children of Oculus arrive. My scuba-loving friends all called it at open water night diving. Even wreck diving was regarded with awe. Cave diving was like being an astronaut.
https://xray-mag.com/technical-diving/cave-diving
Also, the accident reports are NTSB-level in their analysis.
The "Ten Recommendations for Safe Cafe Diving"
1. Always use a single, continuous guideline from the entrance of the cave throughout the dive.
2. Always use the "third rule" in planning your air supply (this means 1/3 to go to where you want to go, 2/3 to return and for emergencies)
3. Avoid deep diving in caves
4. Avoid panic by building up experience slowly and being prepared for emergencies
5. Always use at least three lights per diver
6. Always carry the safest possible scuba.
7. Avoid stirring up silt.
8. Practice emergency procedures with your partner before going diving, and review them often.
9. Always carry the equipment necessary for handling emergencies, and know how to use it.
10. Never permit overconfidence to allow you to rationalize violating recommended safety procedures.
For example the Aquacorps archives on archive.org
https://web.archive.org/web/20020611235343/http://www.cisatl...
At least ten years ago, when I went through cave training, incident reports were a significant fraction of the curriculum between Apprentice and Full Cave certifications. If you weren't in the overhead, you were reading about people who didn't make it back and figuring out how to structurally reduce the risk of suffering the same specific misfortune.
At age 16 (or so), I dived into an undersea cave in Sardinia, pretty much completely unprepared.
I had scuba gear, but only a "waterproof" flashlight (read: not a proper diving lamp by any means), no line, no backups, no nothing. Just a teenager's sense of invincibility.
It was almost literally otherworldly, floating through bone-white passages full of strangely shaped rocks, and being so palpably close to my own fate.
It was also very scary for reasons both objective (I knew it was monumentally stupid going in) and imagined (the darkness beyond the cone of your lamp is full of sharks, giant kraken, and Cthulhu).
I turned around after five minutes. On the way back, noticed a fork in the cave. Had a horrible sinking feeling and cursed myself for not looking back on the way in. Picked a path at random, and apparently picked right.
It was the best experience I never want to repeat again.
"STOP! PREVENT YOUR DEATH! GO NO FARTHER."
Though the best prevention for accidents still seems to be: don't get into a cave without training (and even then!)