First cave dives

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. Last night at about 22:00 2 friends of my son (who was present) were struck by a car whilst they were crossing the road on a pelican crossing. The girl only seemed to have cuts and bruises but the male was paralyzed from the neck down. We have had no further news today. This level of incidents close to home is unusual but it does indicate how random accidents are. I take a similar view of diving and life in general, bad luck can happen.

I feel bad the kid is paralyzed but had he been paying attention he most likely would have not been hit.
its not random at all its not paying attention.
good luck and bad luck don't exist. you make your own "luck"
pretty simple concept- pay attention, don't be stupid, don't get hurt.





I am a qualified risk assessor (most experience for engineering workshops or on chemical / refinery plant). I am also a qualified LRQA Auditor. (ISO 9001 etc). I have also taught (I am a former university lecturer) health and safety, including working in confined space

qualified risk assessor and lecturer on safety? really?? overhead environments are not a joke. far more experienced divers than yourself have died in wrecks and caves. If you die in a wreck or a cave its not an "accident" it was not "wrong place wrong time" it was a diver who had no training no experience and not the proper mindset to be where he was. ultimately he killed himself with a poor decision.

just remember. Everything we know about diving today someone got seriously hurt or killed to figure out.....
 
So I actually kind of get what you're saying here. Take any activity with a 1% chance of a catastrophic outcome, do it 50 times, and your odds are up to a coin flip. What do you think your odds were of not making it out of that cave? What odds would you accept? How many cave dives does that pencil out to? Are you planning to stop before you hit that number? Or will you consider yourself experienced enough at that point to be safe?

Cave divers, what do you think are the odds of a catastrophic outcome in that cave for an untrained cave diver? For a trained cave diver? Is the multiplying of risk with repetition something that's discussed in cave diving courses?


Well first I'm not sure you can quantify risk like a percentage.. it doesn't work like that. Next statistically speaking let's say it was 1%, after 50 dives it still is only 1%, but that 1% can hit you on the first diver the 49th or the 250th...

The point is that you should recognize this risk, and if it's unavoidable through good planning, training, experience, at least make it so that when it hits, you have the means to resolve it.

Every activity carries risks... I'm not saying you can avoid all risks, but at least in context of overhead diving it's already very easy to mitigate the most dangerous risks, or know how to handle them... training... so why not do that if you really like overhead diving?
 
KentB - To some extent what you say supports what I have been saying. Your comments that far more experienced divers die in caves and wrecks support the point I made that the more frequently you partake in an activity the more likely it is something will go wrong. Last Autumn I was shown police diver video footage of 2 divers who had died in a wreck. They were trained and experienced. Although no one knows for sure It seems the wreck silted and their line got cut on sharp metal, certainly their line was cut with frayed ends. You can have a no fault (at least on the part of the injured party) incident through no fault of your own. Examples as follows. 1974 I was doing about 20 / 25 mph on a Honda step through when a drunk driver turned Right across my path. 1980 I was doing about 50mph on an A road, limit 60 mph. A very large lamb shot out of long grass right into my front wheel. I crashed and the farmer was prosecuted for failing to maintain his fences / walls. 1990 motocrossing another rider lost control approaching a corner and ran into me. 1997 I was turning into my own drive when an elderly driver ran into the back of me, after leaving 76 ft skid marks uphill on a dry road. He was pretty well blind in bright sunlight and was forced to surrender his license. Regarding motocrossing, anyone who takes part in this more than briefly can expect to break at least one bone, but as for the other incidents most people think you should be able to use the public roads in reasonable safety. Diving is just the same, cave diving is more comparable to mx whereas open water 20m diving is more comparable to public road use. No one ever has complete control of all the factors that can cause an accident, its how you minimize the risk and deal with any incidents that occur that counts. In the cave I was in I could have coped easily with torch failure, add breathing equipment failure and I still could have coped reasonably easily, if you then added silting / loss of visibility (very unlikely as we were well above the bottom) I would have had a worrying moment or two. However at all times I was very close behind the guide, could probably have grabbed his fin and my buddy was barely an arms length to my left. Normally in OW at less than 20m I do not worry too much about some buddy separation but In a cave I make sure it does not happen. I am not saying what I did was correct by according to diving rules and it could have been made less risky by having 2 guides,more spare air, guideline etc. However this dive in done regularly using the same equipment as on my dive and a large number of participants and the guides consider the risk to be an acceptable level. Certainly it would take a combination of several unlikely occurrences to cause a serious incident or loss of life.
 
Hey 60 plus,

I('m sorry but for me there is really a disconnect between the things you say you are (qualified risk assessor, ISO certified blablabla, lector on health and safety/ working in confined spaces) and what you do underwater, how you evaluate your own activities.

Doesn't make sense to me at all... I'm sorry.

But hey... I had a lot more to write but I'm going to stop. It's no use. Nobody is going to convince you, and that is all fine, I just hope that other divers can navigate through the walls of texts been written (also by me... sorry) and get to the truth that has been told by many people. So this is my last post in this topic.

"An overhead environment is loads of fun, and can be really pretty and exciting BUT it can also throw a lot of silly and possibly dangerous things at you... from losing a mask, a freeflow, navigational issues, loss of visibilty, loss of line, loss of buddy, lights that fail, silty bottoms, percolation, tight spots, etc... Most of these are not such a big issue, if you promptly solve them before they cascade out of control... most of these things probably won't happen... but you don't know what the cave is like until you enter it... so maybe you should be prepared if that benign sea cave just changes his mind and decides to throw something silly at you!? Being prepared, learning how to solve these silly things is not so hard, but needs training... you learn a lot and it is loads of fun... so why not take it if you like sea caves (or caves, or wrecks or every bloody overhead you can imagine!)."
 
Nobody is going to convince you, and that is all fine,
It is not fine. People keep saying this but it is not fine that an individual can ignore all good advice and experience and still go kill himself, thereby bringing on more restrictions and costs and hurdles for those who do not act so selfishly.
 
I can't help but Wonder whether or not 60 plus has been driving all these years with a license. If so, how did he get his license? If he was in MX biking, how did he get into that?
But nevermind, he's decided.
 
Well....... There are old divers.....And there are bold divers..... But there are NO old, bold divers.
 
It is not fine. People keep saying this but it is not fine that an individual can ignore all good advice and experience and still go kill himself, thereby bringing on more restrictions and costs and hurdles for those who do not act so selfishly.

I get the impression this is just how it is--the standard of how safe is "safe enough"--with some of those European sea caves that dive ops routinely take OW divers to. So long as the attitude and potential consequences that you mentioned don't spill over to this side of the pond, maybe that's what is "fine."
 
Well first I'm not sure you can quantify risk like a percentage.. it doesn't work like that. Next statistically speaking let's say it was 1%, after 50 dives it still is only 1%, but that 1% can hit you on the first diver the 49th or the 250th...
What you wrote is not what I said. Yes, your risk is still 1% each time, but your risk overall is greater with each repetition. These are difficult concepts to understand and to reconcile, but they are crucial for anyone engaging in risky activities. Think of a coin flip. Your odds of getting heads is 50% each time, but the odds of getting heads 10 times in a row is much smaller. Of couse, the odds of any set of outcomes (5 heads followed by 5 tails, alternating heads and tails, etc.) are equally slim, but half of the possible outcomes involve half heads, half tails, while 100% heads gets less and less likely the more times you do it. If tails means you die, you'd be a fool to take that bet even once, of course, but even if you did and got lucky, enough repetitions would surely kill you.

Now imagine you're playing Russian Roulette, but with a gun that has 100 chambers and just one bullet. And imagine you don't keep pulling the trigger, which would mean slightly higher odds each time as you use up the empty chambers, but rather you spin it each time, so you have a 1% chance of death each round. In 100 rounds, you would expect the gun to fire once. Maybe it wouldn't; maybe you'd get to round 150 without it going off. Maybe it would go off on the very first round. But even though your odds of death are still 1% each round, they're much higher over the long term if you keep doing it, just like your odds of getting at least one tail increase the more times you flip that coin.

I do think it's at least theoretically possible to quantify any risk as a percentage if you have enough data. I know I don't have anywhere near enough data to make even an educated guess regarding cave dives, and maybe nobody does. But I'm interested in hearing what the experts think.

One place in diving I've heard the 1% risk figure is in the use of dive tables or algorithms; supposedly the risk of getting bent if you dive right to the NDLs is about 1%. Of course, that's the generic you, as opposed to John with a hangover and an undiagnosed PFO, or Jane, with excellent bouyancy control and no history of injuries that might create nucleation sites for bubbles. But either of them would want to bear in mind that figure when planning their dives, because if they both dive 100 times per year and do each dive right up to the limits, they're both eventually going to get bent. If they keep their dives just a bit shorter and shallower, and increase their surface intervals a bit longer, they could reduce their odds to the point that you might expect only one incident per 10,000 or even 100,000 dives, which might give them a chance to die warm in their beds before their number is up.

Suppose for the sake of argument that a diver with good OW skills but no cave training had a 1% chance of dying in that particular cave, and suppose cave training would decrease his risk to .1%. But no one who goes through all that expensive training is going to stop at 10 cave dives. After 100 dives in that cave, the trained diver's risk profile might not be so good. (Of course, his risk would probably drop slightly each time as he gained experience with cave diving and with that particular cave especially, but at that point the math gets really complicated.) In some cases, a brief foray into a dangerous activity might be less risky than making it a regular thing. On the other hand, suppose training reduces your risk from 1% to .01% or even .001%. That would present a much stronger argument for getting the training rather than limiting your exposure, and I suspect that may be closer to the truth.

The other problem is, of course, that humans tend to be selectively rational about these things. Going back to the 1% for untrained vs. .1% for trained divers assumption, is the untrained diver really going to stop at one dive? Or is he going to go along, switching from "I'm managing my risk by not making this a regular thing" to "well, my risk is still only 1% each time," to "I've done this ten times already; I obviously know what I'm doing." That's what I was hinting at in the end of my post addressed to the OP. Being 1% right about risk can sometimes be more dangerous than being 100% wrong.
 
Well first I'm not sure you can quantify risk like a percentage.. it doesn't work like that. Next statistically speaking let's say it was 1%, after 50 dives it still is only 1%, but that 1% can hit you on the first diver the 49th or the 250th...

The point is that you should recognize this risk, and if it's unavoidable through good planning, training, experience, at least make it so that when it hits, you have the means to resolve it.

Every activity carries risks... I'm not saying you can avoid all risks, but at least in context of overhead diving it's already very easy to mitigate the most dangerous risks, or know how to handle them... training... so why not do that if you really like overhead diving?
You can do it, it’s like saying I am happy to dive with 99% safety before I stop diving.

You compute your risk factors so you die statistically only 1% of the time when doing the X dives in your life and live with it. This is a fairly rhetorical and theoretical question because you will not be able to be so precise with factors.

Ultimately you always have a risk and you have to set it to a level you are happy with.
 
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