Eli5: Why is cave diving so dangerous ? To the point people with 20+ years of diving experience refuse to do so.
In: 17403
You can get lost in caves and run out of air.
You can get stuck in a small gap and run out of air.
You can miscalculate how long it will take to resurface (including going slow enough to avoid the bends, which you didn’t have to do on the way down) and run out of air.
You can get your air hoses or valves damaged on sharp surrounding rocks and run out of air.
You can get sucked into somewhere you didn’t want to go by a current.
Here’s a [greentext](http://i.imgur.com/CkEruxw.jpg) about cave diving. I almost always repost this whenever a cave diving topic comes up.
Some caves can have currents like a river. Perfectly fine in this part and then turn a corner and… Whoosh… gone.
Is… this my moment?
I teach cave diving full time for a living.
Besides what Manatee said above, which is all true, what kills people is incorrectly assessing the risk in what they are doing or about to do. Unknown unknowns kill.
That decision could be to go cave diving without training, to go deeper than they have before, to try and fit through a small space or thinking that doing a few more navigations in a complex system is not that risky.
In summary, it ALL boils down to the endless list of possibilities to unknowingly take on a bigger risk/challenge than you are capable of handling. Always seek proper training.
I have posted some videos of both the riskier, and more awesome sides cave diving that you’ll find on my profile.
Edit: @jake_bulman for those who asked
Last time someone asked this, this was my favorite answer:
Many certified scuba divers think they are capable of just going a little deeper, but they don’t know that there are special gas mixtures, buoyancy equipment and training required for just another few meters of depth.
Imagine this: you take your PADI open water diving course and you learn your dive charts, buy all your own gear and become familiar with it. Compared to the average person on the street, you’re an expert now. You go diving on coral reefs, a few shipwrecks and even catch lobster in New England. You go to visit a deep spot like this and you’re having a great time. You see something just in front of you – this beautiful cave with sunlight streaming in – and you decide to swim just a little closer. You’re not going to go inside it, you know better than that, but you just want a closer look. If your dive computer starts beeping, you’ll head back up.
So you swim a little closer and it’s breathtaking. You are enjoying the view and just floating there taking it all in. You hear a clanging sound – it’s your dive master rapping the butt of his knife on his tank to get someone’s attention. You look up to see what he wants, but after staring into the darkness for the last minute, the sunlight streaming down is blinding. You reach to check your dive computer, but it’s a little awkward for some reason, and you twist your shoulder and pull it towards you. It’s beeping and the screen is flashing GO UP. You stare at it for a few seconds, trying to make out the depth and tank level between the flashing words. The numbers won’t stay still. It’s really annoying, and your brain isn’t getting the info you want at a glance. So you let it fall back on your left shoulder, turn towards the light and head up.
The problem is that the blue hole is bigger than anything you’ve even dove before, and the crystal clear water provides a visibility that is 10x what you’re used to in the dark waters of the St Lawrence where you usually dive. What you don’t realize is that when you swam down a little farther to get a closer look, thinking it was just 30 or 40 feet more, you actually swam almost twice that because the vast scale of things messed up your sense of distance. And while you were looking at the archway you didn’t have any nearby reference point in your vision. More depth = more pressure, and your BCD, the air-filled jacked that you use to control your buoyancy, was compressed a little. You were slowly sinking and had no idea. That’s when the dive master began banging his tank and you looked up. This only served to blind you for a moment and distract your sense of motion and position even more. Your dive computer wasn’t sticking out on your chest below your shoulder when you reached for it because your jacket was shrinking. You turned your body sideways while twisting and reaching for it. The ten seconds that spent fumbling for it and staring at the screen brought you deeper and you begin to accelerate with your jacket continuing to shrink. The reason that you didn’t hear the beeping at first and that it took so long to make out the depth numbers between the flashing words was the nitrogen narcosis. You have been getting depth drunk. And the numbers wouldn’t stay still because you are still sinking.
You swim towards the light but the current is pulling you sideways. Your brain is hurting, straining for no reason, and the blue hole seems like it’s gotten narrower, and the light rays above you are going at a funny angle. You kick harder and just keep going up, toward the light, despite this damn current that wants to push you into the wall. Your computer is beeping incessantly and it feels like you’re swimming through mud. Fuck this, you grab the fill button on your jacket and squeeze it. You’re not supposed to use your jacket to ascend, as you know that it will inflate itself as the pressure decreases and you will need to carefully bleed off air to avoid shooting up to the surface, but you don’t care about that anymore. Shooting up to the surface is exactly what you want right now, and you’ll deal with bleeding air off and making depth stops when you’re back up with the rest of your group.
The sound of air rushing into your BCD fills your ears, but nothing’s happening. Something doesn’t sound right, like the air isn’t filling fast enough. You look down at your jacket, searching for whatever the trouble might be when FWUNK you bump right into the side of the giant sinkhole. What the hell?? Why is the current pulling me sideways? Why is there even a current in an empty hole in the middle of the ocean??
You keep holding the button. INFLATE! GODDAM IT INFLATE!!
Your computer is now making a frantic screeching sound that you’ve never heard before. You notice that you’ve been breathing heavily – it’s a sigh of stress – and the sound of air rushing into your vest is getting even weaker.
Every 10m of water adds another 1 atmosphere of pressure. Your tank has enough air for you to spend an hour at 10m (2atm) and to refill your BCD more than a hundred times. Each additional 20m of depth cuts this time in half. This assumes that you are calm, controlling your breathing, and using your muscles slowly with intention. If you panic, begin breathing quickly and move rapidly, this cuts your time in half again. You’re certified to 20m, and you’ve gone briefly down to 30m on some shipwrecks before. So you were comfortable swimming to 25m to look at the arch. While you were looking at it, you sank to 40m, and while you messed around looking for your dive master and then the computer, you sank to 60m. 6 atmospheres of pressure. You have only 10 minutes of air at this depth. When you swam for the surface, you had become disoriented from twisting around and then looking at your gear and you were now right in front of the archway. You swam into the archway thinking it was the surface, that’s why the Blue Hole looked smaller now. There is no current pulling you sideways, you are continuing to sink to to bottom of the arch. When you hit the bottom and started to inflate your BCD, you were now at 90m. You will go through a full tank of air in only a couple of minutes at this depth. Panicking like this, you have seconds. There’s enough air to inflate your BCD, but it will take two minutes to fill, and it doesn’t matter, because that would only pull you up to the top of the arch, and you will drown before you get there.
Holding the inflate button you kick as hard as you can for the light. Your muscles are screaming, your brain is screaming, and it’s getting harder and harder to suck each panicked breath out of your regulator. In a final fit of rage and frustration you scream into your useless reg, darkness squeezing into the corners of your vision.
4 minutes. That’s how long your dive lasted. You died in clear water on a sunny day in only 4 minutes.
EDIT: I’m not author of the above. I saved it from another comment months/years ago because it haunted me. I’m sure if you Google around you could find the og comment.
Lots of good answers in here, but I’ll add another piece.
Humans really aren’t meant to navigate in 3D space. We evolved to track across a 2D plane. The minute you add verticality into the mix, it’s *super* easy to get lost.
I always had this “pfff, how dumb do you have to be to get lost in a cave” mentality, then played Subnautica. My ass drowned in like 20 feet of water because I got lost in an underwater cave system inside of like 60 seconds.
I got a chill down my spine when I realized that I’d gotten that lost while sitting in my chair, warm and cozy. Imagining actually being there, adrenaline pumping and monkey brain taking over because I realized I was getting lost? No chance, my ass would’ve been dead IRL.
Former almost cave certified diver here. Everyone’s mentioned the general dangers pretty well so let me give why I didn’t finish my certificate.
I took a two week vacation to visit a still renown cave instructor. Previously I had done cavern for a few years and even some wreck penetration, aka going into sunk ships. Never so far that I couldn’t reel my way out etc. I’ve done some deeper dives and all in all consider myself a very safe diver who knows his bounds and doesn’t push boundaries.
After my first cert dive I was feeling good. We checked in for the day after and I dropped my backup regulator(breathing mouthpiece) at a shop because it was having a very minor pressure issue after our dives. I swapped to my instructors back up and was good.
Next day arrives and it’s perfect weather perfect water. We get to site, I hook up my backups and take a quick breath underwater to make sure no more leak. We’re good across the board. We sink ourselves down about 60 ft before the underwater caves entrance, it’s about 8 ft wide and goes back 100 or so and doesn’t feed into any cracks or holes you can get lost in.
I go about twenty feet in and all of a sudden notice my regulators not giving me gas each breath. I crank it up and nothing is like breathing through a pinched straw. I grab my backup, take a breath and another and now I have some odd grease lining my mouth. I kick forward and tug on my instructors fin, giving him some sign language he passes me his backup and I take a breath but panic is already screaming through my veins. I signal to him, grab a backup bottle and ascended asap without thinking about how long I was down.
I surface, take my gear off and explain what happens. He disectrd my gear and my main appeared to have no issues, maybe a tiny bit cold but water was in 50s and it was not a cheap reg so probably not a freeze. My octo had been maintenance and it appeared something was leftover somewhere or perhaps the new line. I didn’t care enough to find out and I quit diving then. The instructor did take the gear and said he’d contact vendors if necessary etc.
So yea cave diving is crazy because so many things can go wrong, including yourself. I’m sure I could have checked these things and avoided them, as far as I knew at the time I was.
Really eerie answer (especially towards the end) I saved from three years ago, worth the read. It also has a normalization of deviance video which is pretty enlightening. Echos a lot of what /u/PM_YOUR_MANATEES said.
>You have to learn how to kick properly and hold your buoyancy so that you don’t silt up the cave. Untrained OW divers will rototill with their fins pointed down and even if they’re floating in the water column they’ll be blowing out the viz behind them. If they’re not neutral and they crash into the bottom then that’s really going to blow the silt out there.
>We’re trained to know roughly what the failure rates and causes is of all our equipment and how to handle failures and emergencies under water. So we carry 3 lights and we have at a minimum dual tanks with full gas redundancy. We know the burntimes of our light and we plan our gas so that we have enough gas to both get us out and to exit with our buddy if they have a gas emergency.
>We follow a line into and out of the cave, since different sections of the cave may look similar and since going out may look different than coming in and following the cave may be disorientating.
>There’s also just mentality which is taught. If you are back in a cave and have some kind of issue and stop and futz with it for 10 minutes then you’re slowly dying. It can be better to make progress to your exit, while cleaning up your equipment on the move (or trying to figure out what to do about a failure). At the same time any failures that will slow down your exit you probably should stop and address (if you’re 60 minutes back in a cave and you have some issue that will ultimately delay your exit by 10 minutes, its better to spend a minute or two to clean it up — its also usually better not to stack up multiple failures you’ve ignored which is how you start to swirl around the incident pit).
>We don’t actually think about this all the time though or we wouldn’t do it. You’re trained to the point where all of this is just second nature and you just dive into the cave and enjoy it mostly.
>What kills trained cave divers, though, is usually complacency of one form or another. For example there’s the rule that you must have a continuous guideline to open water that is maintained at all times. Very often cave divers start to slack on this rule in caves they think they know and they start not running reel into the cave or start taking jumps from one line to another without putting in jump spools to maintain their continuous guideline. Eventually those rule violations will catch up to you (which is normalization of deviance
).
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byu/Shits_Kittens from discussion
inthalassophobia
I watched an interview with the guy who had to anesthetise the boys before they could be rescued from the Thai cave. There were the equivalent of Thai Navy SEALs working on that rescue who panicked and became disoriented due to the horrific conditions in the caves – at least one of them died.
Having seen that interview, I can’t think of any situation I’d less want to be in than cave diving, the story he told was fucking terrifying.
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