
Basic Cave Diving: A Blueprint for Survival (1986) [pdf] - wallflower
https://nsscds.org/wp-content/uploads/2018/05/Blueprint-for-Survival.pdf
======
breals
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"

~~~
x0x0
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.

~~~
gaius
_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.

~~~
CompelTechnic
Do the guide lines have any indicators that would show which way goes further
into the cave and which way heads toward the surface?

~~~
callahad
Most popular caves have permanent lines installed with arrows every ~100 ft or
so, maintained by the local community. A common convention is that the main /
most navigable path through a system uses a slightly thicker, yellow nylon
line (the "gold line"), while side passages tend to use thinner, white nylon.
Divers are expected to bring their own reels and markers into the cave to make
and mark temporary connections, for example, from open water to the gold line,
or jumps from a permanent line into side passages. Reels are also useful tools
for locating lost guidelines in zero visibility.

There's an overview of various line markers at [https://www.tdisdi.com/cave-
diving-directional-and-non-direc...](https://www.tdisdi.com/cave-diving-
directional-and-non-directional-markers-101/), 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](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."

------
sho
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
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-
at...](https://www.undercurrent.org/blog/2009/09/10/diving-shark-attack/)

[http://www.tampabay.com/news/publicsafety/hernando-county-
au...](http://www.tampabay.com/news/publicsafety/hernando-county-authorities-
searching-wildlife-refuge-for-missing-divers/2158541)

------
oligus
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
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.)

------
stevep98
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
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?

~~~
21
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-
na...](https://www.theguardian.com/world/2018/jul/06/former-thai-navy-seal-
diver-saman-kunan-dies-from-lack-of-air-inside-cave)

~~~
arethuza
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.

~~~
vkou
Wreck salvage. It's not quite the same skillset as cave diving, but wrecks
have many very similar hazards.

Of course, the most dangerous person is someone who thinks they know what they
are doing.

------
21
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
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
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.

------
wallflower
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
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.

~~~
callahad
The IUCRR maintains a few public incident reports at
[http://www.iucrr.org/](http://www.iucrr.org/). Look under the"Accident
Analysis" heading on the left.

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.

------
Daviey
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.

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

~~~
callahad
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."

------
raverbashing
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!)

