8 ms·

Basic Cave Diving: A Blueprint for Survival (1986) [pdf]

77 points by wallflower 8y ago

breals 8y ago
I know this was posted due to the Thai cave rescue but what is discussed in this manual and what they are doing are different. Exley wrote this because scuba divers, some even experienced cave divers, were dying in cave diving accidents and landowners in Florida were closing caves or banning diving. This blueprint is more accident/incident analysis than training material. It was required reading when I got cave trained ~17 years ago. 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"
- planteen 8y ago
  I visited Nacimiento del Río Mante on a spring break caving trip to Mexico ten years ago. We were a group of dry cavers headed back from the Aquismon area. We camped by the spring and I fondly remember swimming on top at night and exploring the small amount of dry cave there. The stream of water coming up was ridiculously strong and very warm. It was a surreal feeling, looking up at the stars and moon, knowing that below your feet there was almost a thousand feet of water extending hundreds of feet below sea level. I remember thinking that Exley's depth record there felt like reaching the moon in terms of exploration.
- paulcole 8y ago
  I grew up in Florida near some popular diving caves. One of the most memorable bits of local apocrypha was about the dead divers they pulled out. 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.
- x0x0 8y ago
  For people who've never had the experience, it's stunning how fast a stray kick into the silt can turn the water in a cave pitch black. Like barely able to see your hand dark. Even when you're used to it most people will find it very claustrophobic. 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.
  - TeMPOraL 8y ago
    > For people who've never had the experience, it's stunning how fast a stray kick into the silt can turn the water in a cave pitch black. Like barely able to see your hand dark. Even when you're used to it most people will find it very claustrophobic. 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.
    - callahad 8y ago
      In practice, the training is excellent and you'll have dozens of zero-visibility experiences before finishing the certification. You learn that as long as you have the line in your hand and you stuck to your gas limits, you have everything you need to make it out alive, even if it takes you twice as long to do so. ...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.
  - gaius 8y ago
    From the surface, it's easy to say just follow the guide cables the divers have no doubt installed Someone asked my cave instructor, if you lose the line how long should you search for it? The rest of your life, he replied.
- astr0n0m3r 8y ago
  I didn't think a silt out was relevant to this cave.
wallflower 8y ago
I posted this because, of course, of the ongoing rescue operation but more for the helicopter pilot-like checklists to stay safe and stay alive. I understand that recommendation #4, #7, and #8 are practically nil'd in the case of the Thai rescue operation (cold iced coffee-like water and the untrained, not-in-great-health kids). 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 https://xray-mag.com/technical-diving/cave-diving Also, the accident reports are NTSB-level in their analysis. https://caves.org/pub/aca/ https://caves.org/pub/aca/ 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.
- mediocrejoker 8y ago
  Are those accident reports publicly available online? The site you linked seems to have a one line summary of each accident but no link to further details.
stevep98 8y ago
I am very interested in learning about the project management/logistics of the operation in the cave. 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.
- arethuza 8y ago
  Are there any armed forces doing cave diving - I know that US SEALs and UK SBS (and others) do a lot around diving but cave diving would looks like a specialism that wouldn't have much direct military relevance?
  - dsfdsfsd423423 8y ago
    I've read in some articles that there are no military divers specialized in cave diving. Experienced private cave divers are of more help here.
  - 21 8y ago
    Well, a so called former Thai Navy SEAL died during this rescue operation, so I guess they are. https://www.theguardian.com/world/2018/jul/06/former-thai-navy-seal-diver-saman-kunan-dies-from-lack-of-air-inside-cave https://www.theguardian.com/world/2018/jul/06/former-thai-na...
    - arethuza 8y ago
      I'm sure special forces are incredibly tough and very skilled - I was just wondering whether there would be any reason for them to train in the skills relevant to cave diving.
      - 8y ago
sho 8y ago
Based on what I know about cave diving, it seems both terrifyingly dangerous and also just plain terrifying. Just this image is enough to put me off forever: http://i.imgur.com/7Vr7F1r.jpg http://i.imgur.com/7Vr7F1r.jpg
- Yizahi 8y ago
  Cave diving stories linked on Reddit recently: https://www.bbc.com/news/magazine-36097300 https://www.bbc.com/news/magazine-36097300 https://www.outsideonline.com/1922711/raising-dead https://www.outsideonline.com/1922711/raising-dead https://www.undercurrent.org/blog/2009/09/10/diving-shark-attack/ https://www.undercurrent.org/blog/2009/09/10/diving-shark-at... http://www.tampabay.com/news/publicsafety/hernando-county-authorities-searching-wildlife-refuge-for-missing-divers/2158541 http://www.tampabay.com/news/publicsafety/hernando-county-au...
oligus 8y ago
I watched a cave diving documentary a few years ago about finnish divers that lost a couple of friends while diving. The film was about the rescue of the bodies and is called "Diving into the unknown". After watching that, the dangers of cave diving were quite clear. Highly recommended for people interested in the subject
- Pyxl101 8y ago
  Detailed BBC article about that accident and recovery, the same accident on which "Diving into the Unknown" is based: https://www.bbc.com/news/magazine-36097300 https://www.bbc.com/news/magazine-36097300 Also recently on HN, "British divers at heart of Thai cave rescue among best in world": https://news.ycombinator.com/item?id=17448311 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.)
- deleted 8y ago
  [deleted]
21 8y ago
Since there is a considerable risk of panic here, do you think that the rescuers will either pre-sedate the boys, or have sedatives on them to administer if they panic? Is there any sedative available which calms you down without also reducing your cognitive/motor capabilities?
- Timpy 8y ago
  I know almost nothing about cave diving, but I can't imagine sedating the people being rescued would be a good idea. Is sedating people in cave diving emergencies a normal thing?
  - pacificpendant 8y ago
    In one of the TV interviews a cave rescuer talked about a rescue where an inexperienced diver was restrained whilst being brought out of a tunnel. Given the distances involved here it would seem unlikely they would sedate them. 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.
- soneil 8y ago
  I'm not sure the children's cognitive abilities are particularly relevant, as blunt as it sounds. It's not like in the last 2-3 days they've trained them to a level beyond the Thai SEAL who didn't make it. 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.
raverbashing 8y ago
Wow, depth blackout is scary Though the best prevention for accidents still seems to be: don't get into a cave without training (and even then!)
rschulman 8y ago
1. Reconsider whether you actually need to dive into this cave...
- callahad 8y ago
  That's pretty much the first line of the standard warning sign you see underwater: https://pbs.twimg.com/media/CkwjzltUUAEjHvV.jpg https://pbs.twimg.com/media/CkwjzltUUAEjHvV.jpg "STOP! PREVENT YOUR DEATH! GO NO FARTHER."
Daviey 8y ago
Would thoroughly recommend reading "The Last Dive: A Father and Son's Fatal Descent Into the Ocean's Depths Paperback" by Bernie Chowdhury. It features the author of this pdf, Sheck Exley quite extensively.

77 points by wallflower 8y ago

I know this was posted due to the Thai cave rescue but what is discussed in this manual and what they are doing are different. Exley wrote this because scuba divers, some even experienced cave divers, were dying in cave diving accidents and landowners in Florida were closing caves or banning diving. This blueprint is more accident/incident analysis than training material. It was required reading when I got cave trained ~17 years ago. 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"

planteen 8y ago
I visited Nacimiento del Río Mante on a spring break caving trip to Mexico ten years ago. We were a group of dry cavers headed back from the Aquismon area. We camped by the spring and I fondly remember swimming on top at night and exploring the small amount of dry cave there. The stream of water coming up was ridiculously strong and very warm. It was a surreal feeling, looking up at the stars and moon, knowing that below your feet there was almost a thousand feet of water extending hundreds of feet below sea level. I remember thinking that Exley's depth record there felt like reaching the moon in terms of exploration.
paulcole 8y ago
I grew up in Florida near some popular diving caves. One of the most memorable bits of local apocrypha was about the dead divers they pulled out. 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.
x0x0 8y ago
For people who've never had the experience, it's stunning how fast a stray kick into the silt can turn the water in a cave pitch black. Like barely able to see your hand dark. Even when you're used to it most people will find it very claustrophobic. 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.
- TeMPOraL 8y ago
  > For people who've never had the experience, it's stunning how fast a stray kick into the silt can turn the water in a cave pitch black. Like barely able to see your hand dark. Even when you're used to it most people will find it very claustrophobic. 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.
  - callahad 8y ago
    In practice, the training is excellent and you'll have dozens of zero-visibility experiences before finishing the certification. You learn that as long as you have the line in your hand and you stuck to your gas limits, you have everything you need to make it out alive, even if it takes you twice as long to do so. ...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.
- gaius 8y ago
  From the surface, it's easy to say just follow the guide cables the divers have no doubt installed Someone asked my cave instructor, if you lose the line how long should you search for it? The rest of your life, he replied.
astr0n0m3r 8y ago
I didn't think a silt out was relevant to this cave.

wallflower 8y ago

I posted this because, of course, of the ongoing rescue operation but more for the helicopter pilot-like checklists to stay safe and stay alive. I understand that recommendation #4, #7, and #8 are practically nil'd in the case of the Thai rescue operation (cold iced coffee-like water and the untrained, not-in-great-health kids). 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 https://xray-mag.com/technical-diving/cave-diving Also, the accident reports are NTSB-level in their analysis. https://caves.org/pub/aca/ https://caves.org/pub/aca/ 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.

mediocrejoker 8y ago
Are those accident reports publicly available online? The site you linked seems to have a one line summary of each accident but no link to further details.

stevep98 8y ago

I am very interested in learning about the project management/logistics of the operation in the cave. 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.

arethuza 8y ago
Are there any armed forces doing cave diving - I know that US SEALs and UK SBS (and others) do a lot around diving but cave diving would looks like a specialism that wouldn't have much direct military relevance?
- dsfdsfsd423423 8y ago
  I've read in some articles that there are no military divers specialized in cave diving. Experienced private cave divers are of more help here.
- 21 8y ago
  Well, a so called former Thai Navy SEAL died during this rescue operation, so I guess they are. https://www.theguardian.com/world/2018/jul/06/former-thai-navy-seal-diver-saman-kunan-dies-from-lack-of-air-inside-cave https://www.theguardian.com/world/2018/jul/06/former-thai-na...
  - arethuza 8y ago
    I'm sure special forces are incredibly tough and very skilled - I was just wondering whether there would be any reason for them to train in the skills relevant to cave diving.
    - 8y ago

sho 8y ago

Based on what I know about cave diving, it seems both terrifyingly dangerous and also just plain terrifying. Just this image is enough to put me off forever: http://i.imgur.com/7Vr7F1r.jpg http://i.imgur.com/7Vr7F1r.jpg

Yizahi 8y ago
Cave diving stories linked on Reddit recently: https://www.bbc.com/news/magazine-36097300 https://www.bbc.com/news/magazine-36097300 https://www.outsideonline.com/1922711/raising-dead https://www.outsideonline.com/1922711/raising-dead https://www.undercurrent.org/blog/2009/09/10/diving-shark-attack/ https://www.undercurrent.org/blog/2009/09/10/diving-shark-at... http://www.tampabay.com/news/publicsafety/hernando-county-authorities-searching-wildlife-refuge-for-missing-divers/2158541 http://www.tampabay.com/news/publicsafety/hernando-county-au...

oligus 8y ago

I watched a cave diving documentary a few years ago about finnish divers that lost a couple of friends while diving. The film was about the rescue of the bodies and is called "Diving into the unknown". After watching that, the dangers of cave diving were quite clear. Highly recommended for people interested in the subject

Pyxl101 8y ago
Detailed BBC article about that accident and recovery, the same accident on which "Diving into the Unknown" is based: https://www.bbc.com/news/magazine-36097300 https://www.bbc.com/news/magazine-36097300 Also recently on HN, "British divers at heart of Thai cave rescue among best in world": https://news.ycombinator.com/item?id=17448311 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.)
deleted 8y ago
[deleted]

21 8y ago

Since there is a considerable risk of panic here, do you think that the rescuers will either pre-sedate the boys, or have sedatives on them to administer if they panic? Is there any sedative available which calms you down without also reducing your cognitive/motor capabilities?

Timpy 8y ago
I know almost nothing about cave diving, but I can't imagine sedating the people being rescued would be a good idea. Is sedating people in cave diving emergencies a normal thing?
- pacificpendant 8y ago
  In one of the TV interviews a cave rescuer talked about a rescue where an inexperienced diver was restrained whilst being brought out of a tunnel. Given the distances involved here it would seem unlikely they would sedate them. 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.
soneil 8y ago
I'm not sure the children's cognitive abilities are particularly relevant, as blunt as it sounds. It's not like in the last 2-3 days they've trained them to a level beyond the Thai SEAL who didn't make it. 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.

raverbashing 8y ago

Wow, depth blackout is scary Though the best prevention for accidents still seems to be: don't get into a cave without training (and even then!)

rschulman 8y ago

1. Reconsider whether you actually need to dive into this cave...

callahad 8y ago
That's pretty much the first line of the standard warning sign you see underwater: https://pbs.twimg.com/media/CkwjzltUUAEjHvV.jpg https://pbs.twimg.com/media/CkwjzltUUAEjHvV.jpg "STOP! PREVENT YOUR DEATH! GO NO FARTHER."

Daviey 8y ago

Would thoroughly recommend reading "The Last Dive: A Father and Son's Fatal Descent Into the Ocean's Depths Paperback" by Bernie Chowdhury. It features the author of this pdf, Sheck Exley quite extensively.