43 replies to this topic

[rstark]

Confessions of a Mortal Diver

[wetpixel]

Um.

After the first gauge problem, I thought: "ok... so he screwed up."

when I got to the end, I was thinking," what a dumbass."

[Cybergoldfish]

Yep, that's enough to give anyone dick pyle's!

[Evil Bill]

Interesting story. He was involved in the Coral Reef Adventure Imax. He had the deepest dives.

[wetpixel]

I guess it's different if you have to do what he did for your job. But.. it still seems excessively naive to use the same sticky gauge AGAIN after it has already failed you once. I also don't think I would have gotten in the water again so quickly after getting the bends.

[Patterns]

Personally I'm not sure that the "job" aspect of this makes much difference. Choosing to do a job in a way which involves taking significant risks is a matter of attitude, just as much as ignoring the warning signs and taking a risk on an individual dive.

Someone who thinks he/she is invulnerable is much more likley to be be injured, whether in diving or in any other activity where safety guidelines are needed.

I understand that it's very common to ignore some safety rules, and not just in diving. Each time a safety rule is breached and there is no adverse consequence, we tend to learn from the experience by concluding that the safety rule is too stringent. But the safety rules are set such that an accident is very unlikely. If we breach the rules "by a small amount" then still most times nothing would go wrong ... but the probability is worse. The worse the breaches, the worse the probabilities.

It's like playing Russian Roulette ... strictly following the safety guidelines is like having a gun with 100000 chambers, and a bullet in only one. Ignoring the rules so blatantly is like having 6 chambers and 1 bullet. Then if the first 3 times I play, there's no disaster, does that mean I should conclude it's safe enough to play with 6 chambers?

Depends on your attitude to risk.

-David

[Cybergoldfish]

Each time a safety rule is breached and there is no adverse consequence, we tend to learn from the experience by concluding that the safety rule is  too stringent.

Lots of good points David, and summarised this is called complancy - A desease we all suffer from in certain degrees; day in, day out, and whilst diving too. However, not every individual, thank goodness is so blatently stupid.

"I could easily walk across that high-wire yesterday, and the day before!"

[craig]

Each time a safety rule is breached and there is no adverse consequence, we tend to learn from the experience by concluding that the safety rule is  too stringent.  But the safety rules are set such that an accident is very unlikely.  If we breach the rules "by a small amount" then still most times nothing would go wrong ... but the probability is worse.  The worse the breaches, the worse the probabilities.

The trouble is that our "safety rules" are inconsistantly established and are often pulled out of someone's butt. Take, for example, the ridiculous oxygen exposure tables for nitrox or the constant ascent rate "rule" regardless of depth. How will anyone get injured holding their breath on descent? Some of these rules have little or no bearing on a diver's ultimate safety and tend to undermine peoples' respect for the rules that do. Often the rule is chosen based on what is easy to teach rather than what makes sense or actually works.

On the other hand, divers are eager to forget or blatantly disregard their training in order to get more bottom time. On my last trip, I used a new computer (Suunto Vytec) which consistently gave me less bottom time than everyone else. Their advice was to get a computer that gave more bottom time. "No use doing a extended safety stop after my 100 foot dive", they think, "I only went one bar into the yellow.". On another trip, my dive buddy switched from Nitrox to air because her new nitrox computer (set properly) gave her less bottom time than her old Solution did. "So why use nitrox?" she asked. This is the kind of critical thinking that is commonplace in diving today.

So what we have is too little respect for the risks of diving combined rules that are sometimes ridiculous. This is what happens when we try to pump out as many recreational divers as we can for fun and profit. I blame the PADI mentality.

Related to this, one of my best friends growing up joined the Air Force in order to pay for his medical school education. In the service, his specialty was hyperbaric medicine and by that time he was already a recreational diver. The two things he said to me that stuck in my mind were (1) overexpansion injuries are virtually impossible unless a diver has a mechanical sensitivity to them, and (2) he would never dive deep again. When asked about the first point, he said that the vast majority of us are not at risk, but we all need to be careful. When I asked him to define deep diving, he said 60 feet. All of us take for granted our safety more than we probably should.

Ultimately, the only safety rule that makes accidents unlikely is not to dive. We have to accept the risks we face, understand what's happening to our bodies and use our brains. As far as the diver in the story goes, he too easily attributes his mistakes to teenage invulnerability. He was, and still is, a "dumbass".

[Cybergoldfish]

To Quote Craig's Very valid observations and points, and add:

Q.The trouble is that our "safety rules" are inconsistantly established and are often pulled out of someone's butt. Some of these rules have little or no bearing on a diver's ultimate safety and tend to undermine peoples' respect for the rules that do. Often the rule is chosen based on what is easy to teach rather than what makes sense or actually works.

A. Absolutely correct, This is very often the case: They are often there as a cover-your-ass litigation issue as prescribed by certain mass-production agencies. They have little or no baring on the real issues confronting divers who find them self in trouble. Especially that often fatal first time, as more often than not these issues were not taught by people qualified to do so, and couldn't fully understand the implications themselves.
As a novice I would have prefered to know more about decompression theory, self survival in the unlikely event of, and maybe a few real facts like why all your skin would drop off well before inwater decompression would cure your DCS.

Q.Take, for example, the ridiculous oxygen exposure tables for nitrox or the constant ascent rate "rule" regardless of depth. How will anyone get injured holding their breath on descent?

A. Yes, the Nitrox system sucks - Main reason: Adjusting the tables removed any benefit the extra oxygen had in the mix. Never too many films around of people having convulsions so students can see what happens on too rich a mix for an intended depth.

"Nitrox gives me more bottom time..." Bullsh!t, You still have the same size cylinder as anyone else and you still breath at the same rate as you did on air!
IMO It should have stayed a 'Stop Gas'. Plus how do you readily treat a bent, convulsing nitrox diver?
This is one of the Big issues both Karl Shreeves (Commander Data) and I had with the stuff before PADI started marketing the courses.
"Yes, You can become a mixed gas professional in just a few controled dives." - Can you £*&^!

Holding your breath on descent can cause lung collapse and all manner of squeezes, this is why free diving is not open to everyone.

The dumbass conclusion I think is unanimous but the story I though is something that should be Mandatory reading material in all courses.

Also the word 'Divemaster' often has so much illharity contained within it and so much sadness too, as 60 dives or so in a lake is all the practical experience that's needed.

[craig]

Holding your breath on descent can cause lung collapse and all manner of squeezes, this is why free diving is not open to everyone.

Yes, particularly when you use a sled to rocket you down from the surface to 300 feet!

I certainly don't advocate breath holding on descent with scuba of course. The point is that the "don't hold your breath rule" should be "always be aware of your bouyancy, keep your airway clear on ascent, breathe naturally, and understand that a lung full of air could cause an unintended ascent". Of course, "overexpansion injuries are very bad" goes without saying, too. The trouble is, the latter is harder to teach in these days of dumbing down and covering up.

In reading this, all I could think was what it would take for me to have made the same sequence of poor decisions. Then there was the pit in my stomach as he described his injuries. Finally, I wondered how I would avoid the same fate and concluded that I should not plan solo bounce dives to 200+ feet on air without a redundant supply, avoid blow-n-go emergency ascents for 200+ feet after 15+minutes of bottom time at extreme depth. and finally skip the "lather-rinse-repeat" process that sealed his doom.

[Cybergoldfish]

I concur...

[Patterns]

Often the rule is chosen based on what is easy to teach rather than what makes sense or actually works.

I actually think this is appropriate for beginners. And for more experienced divers, it's still appropriate to have a default mode of behaviour which is safe.

Take the "don't hold your breath" rule.

Especially when somebody is learning to dive, there is a lot to think about at one time. In this situation, it's important to keep the rules as simple as possible, and to keep beginning divers in situations in which they are unlikely to suffer any serious consequences even if they make a big mistake.

I understand from my reading that it's virtually impossible to suffer from any DCS effects if dives are limited to about 10m. And new divers' first dives are not deeper than this. At that depth, what sorts of things could go wrong? Even if the equipment fails, it's easy to swim to the surface from that depth without taking a breath. There are other divers around all the time, lots of alternate air sources... in other words, lots of safety backups.

However, at shallow depths, lung overexpansion injuries are more likely. Ascending from 40m to 30m while holding breath would see the air in the lungs expand by 25%. But from 10m to the surface brings an expansion of 100% - providing the best possible chance of such an overexpansion injury. And that emergency ascent to the surface is an obvious possibility to a panicked new diver.

So a good way to reduce the likelihood of this potential serious accident that could befall a diver on his/her first dives is to make a discipline of "never hold your breath".

Of course there are many situations in which holding your breath won't result in any problem. Probably that's almost every situation, in fact! I do actually think it's a good idea to regard this rule as a default, and only ever hold breath by consciously deciding to depart from normal procedure, because in an emergency - the most likely situation for a fast buoyant ascent - people are less likely to remember to do something important if it is not a normal part of their behaviour.

This is just an example where as it happens I think I know enough to comment. My point is that a large part of safety in a lethal environment (I certainly can't breathe water!) is to have automatic patterns of behaviour which are safe and will continue to be safe even if one day I panic and don't pay attention to them. From this point of view, very simple consistent rules that can be a standard part of behaviour are very much safer because they are more likely to be followed in an emergency situation.

As we learn more, and have confidence in our ability to stay calm in an awkward situation, it's (by personal decision) appropriate to relax some safety requirements to reach consistency in the "riskiness" of the various procedures we rely on. But each extra thing we have to remember to do differently from usual in an emergency is a potential source of injury or death.

Having said all that, I do think it would be nice if the degree of conservatism in all the safety rules was consistent. Inconsistencies do tend to undermine our respect for the rules that matter... It would also be nice to have a better idea of the riskiness of breaking the rules ... I'd like to be able to make my own assessments of risk but I don't have enough information.

-David

[Patterns]

Didn't realise I wrote so much ...

[Kasey]

I'm with David on this one. I think PADI has done a great job of bringing SCUBA to the masses - with a safety record better than virtually any other sport.

I was only certified 4 years ago, under the PADI system. I've furthered my SCUBA education by taking additionaly courses and by reading everything I can get my hands on. I can intelligently pick and choose situations in which I may stretch PADI's recommendations.

I think that you must oversimplify when teaching open water. THis makes SCUBA available to almost anyone, and benefits us all as the sport becomes more popular.

Re: nitrox
I'm surprised that Bob isn't using nitrox almost routinely. I use it consistently on dive trips, and it does safely allow more dive time at 60-90ft

[Cybergoldfish]

I think that you must oversimplify when teaching open water.  THis makes SCUBA available to almost anyone, and benefits us all as the sport becomes more popular.

Re: nitrox
I'm surprised that Bob isn't using nitrox almost routinely.  I use it consistently on dive trips, and it does safely allow more dive time at 60-90ft

No you shouldn't over simplify initial courses - OW, the very nature of the qualification is misleading and having pulled out 11 people in various states of deadness with this qualification I can comment with some qualification.

Unfortunately, a lot of people do not take studying as seriously as you or I!
Nitrox:

No, I have a CNS that I value too highly. Nitrox has no advantage to me what-so-ever and I do 400+ dives a year.

[tshepherd]

Nitrox has no advantage to me what-so-ever and I do 400+ dives a year

I'm surprised to hear you be so black and white on this one Bob! How about Trimix? Or O2 for decompression stops above 30 ft (10m) on deep dives? I'd say there are reasons for each of the different mixes. I personally prefer Nitrox for dives between 50-100 fsw (the majority of dives I do in places like Cozumel). I definitely feel better using Nitrox, and the increased O2 does give a little bit of a margin of safety when used properly. Above 100 ft or so, I tend to either use air, or a very light mix of EANx, like around 24-26%. Beyond that it's air for now, and trimix later this year once I finish my mixed gas certification.

As for "Open Water" certification, I've got mixed emotions on this one. I can understand why PADI and the other agencies have simplified the initial courses in an effort to make it more appealing to the masses, and as a result have gotten more people dving. Having taken courses from SSI and from IANTD, there is a significant difference in the depth of information between your average OW course, and the courses offered by the smaller, more "tech-focused" agencies. I would guess that your average diver would not make it through the basic certifications if the courses were as comprehensive as they should be. Maybe that would be the safest option, but it would really limit the number of divers, and therefore the industry as a whole that relies on those increased numbers.

That being said, I'd like to see the certifying agencies rethink their classifications. The idea of a PADI diver being an "Advanced Open Water" diver after around 12 dives (I think) is simply ridiculous. Many students I've met have gotten their OW certifications without ever setting foot outside a lake or quarry, which is not exactly open water. This is especially dangerous in areas of the world like the Northeast US, Pacific NW, and any other low vis cold water location. Seeing an OW diver on a wreck dive in NJ for the first time is scary. The problem is one of competition at that point. Too many people are caught up in the titles that a few dives bring them. Who wants to be a basic entry level diver with Agency X when you could be a Master diver with Agency Y?

Anyway, I'll get off my soapbox now...

[craig]

No you shouldn't over simplify initial courses - OW, the very nature of the qualification is misleading and having pulled out 11 people in various states of deadness with this qualification I can comment with some qualification.

Unfortunately, a lot of people do not take studying as seriously as you or I!

No, you shouldn't. The goal needs to be to produce qualified divers, not pump out as many certs as possible. People need to understand what's going on before putting their life and health in jeopardy. It's not hard either.

Kasey, on what basis do you claim that PADI has "a safety record better than virtually any other sport"?

[Kasey]

DAN's annual report reported an injury rate of about 9 per 10000 partiicpants (don't quote me on the exact number) - 10 fold lower than soccer. Even safer than bowling. With that kind of safety record I find it difficult to accept that the training is insufficient. I agree that there is a great deal more to learn after an OW cert, but the same can be said for a new driver, pilot, etc. Some responsibility must fall on the student to develop his skills and abilities.

[Reefkeep]

I have to admit I only dive Nitrox in the US. For me it only took one trip to the chamber to get me to switch to 32%. Thats another story....

"Nitrox gives me more bottom time..." Bullsh!t, You still have the same size cylinder as anyone else and you still breath at the same rate as you did on air!

Thats not thinking outside the box, if you have more bottom time (table time) then why not get bigger tanks? Thats what I do, I dive with HP 100s now. (Over filled)

One of my dive buddys who has "logged 5000+ dives" and has "been teaching / diving since before I was born" stated over and over for years that Nitrox is bad stuff! ...LOL...He was diving Trimix on Sunday....Kind of reminds me of some of you.

[Reefkeep]

Tshepherd be carefull in Cozumel with Nitrox, I have gotten up to 50% mix that had been marked at 36%. Don't let them test it with the dive shop gear, bring your own O2 analyzer.