Instructor bent after running out of air at 40m

[ANDYCA]

A&I is a great forum for accident analysis. These threads often let us bring up a wide range of possible failure modes, and discuss hypotheticals that are great for learning and teaching.

I would say that 95% of the time, there is never any "official report" available to the public, and dive profiles are rarely available either.

That doesn't make the discussion pointless. This isn't a legal deposition about this specific case. The actual case itself is usually a starting point for a wider conversation.

I agree in general, I was referring to this in the specific context of page 21 of a forum post where many theories have been put forward but no one knows what really happened without asking Osborn himself. After 9 years it's probably time to stop picking the scab on this particular one.

I was also hoping they were BSAC divers and had filled in a BSAC incident report, sadly even today pride often comes before safety, it can be very difficult to convince some divers to fill in those reports so others can learn from their mistakes.

It has made me think a bit about SPG check complacency on dives though, I'm diving twin 12L at 232bar... I probably check my own air 4-5 times during a dive but I check my buddies single cylinders far more often.. as I never finish a days diving (2 dives) with less than 100bar. A few weeks ago I finished on a couple of days with 170bar.
I'm going to start checking more often just so I have the muscle memory for the odd times when I do longer deeper dives with more experienced buddies.

 

[dmaziuk]

That is usually the case with accidents though.

"Accident" strongly implies unexpected, with no deliberate cause. If you're doing things you shouldn't be doing, calling the outcome "unexpected" is a bit of stretch.

 

[KenGordon]

"Accident" strongly implies unexpected, with no deliberate cause. If you're doing things you shouldn't be doing, calling the outcome "unexpected" is a bit of stretch.

So the event that occurs to a car travelling at 71mph on a U.K. motorway that results in a car upside down on the banking, what would that be called? Now again at 90 mph, in the snow?

You think he set out to get bent? The problem is the error of judgement that led the people doing the dive to not expect this outcome.

Failure to recognise how important judgement is and how it can be badly wrong even while people are not getting hurt is a problem. That is what leads to the whole normalisation of deviance thing.

 

[dmaziuk]

So the event that occurs to a car travelling at 71mph on a U.K. motorway that results in a car upside down on the banking, what would that be called? Now again at 90 mph, in the snow?

You think he set out to get bent? The problem is the error of judgement that led the people doing the dive to not expect this outcome.

I believe when your parents tell you to not screw around with the gun because you'll shoot your eye out, and you screw around with the gun and shoot your eye out, that argument breaks down.

Yes, you made an error of judgement and did not expect to shoot your eye out.

No, it was not unexpected.

I said before, I don't particularly care about your eye. What boggles my mind is someone would go on the telly and tell "mu-um, the gun was hanging on the wall and I never came near it and it just shot all of its own accord and hit me in the eye" story and not expect the fallout that is happening.

 

[caruso]

"Accident" strongly implies unexpected, with no deliberate cause. If you're doing things you shouldn't be doing, calling the outcome "unexpected" is a bit of stretch.

I'm sure they didn't expect to get bent regardless of their irresponsible and reckless decisions. Just like a person doesn't expect to get in a car accident when they drive while impaired.

 

[dmaziuk]

I'm sure they didn't expect to get bent regardless of their irresponsible and reckless decisions. Just like a person doesn't expect to get in a car accident when they drive while impaired.

In the case of DUI accidents, the courts appear to think it's not a "normalization of deviance" nor an excuse.

(All analogies suck but car analogies tend to turn around and bite your argument in the back the moment you let them out.)

 

[KenGordon]

In the case of DUI accidents, the courts appear to think it's not a "normalization of deviance" nor an excuse.

(All analogies suck but car analogies tend to turn around and bite your argument in the back the moment you let them out.)

It doesn’t matter if you have an accident or not, driving while drunk is illegal. It is still an accident though.

Accidents have causes. Given enough people doing a thing then you can EXPECT accidents. Just because the out come is expected some of the time doesn’t make it not an accident.

 

[KeithG]

It doesn’t matter if you have an accident or not, driving while drunk is illegal. It is still an accident though.

Accidents have causes. Given enough people doing a thing then you can EXPECT accidents. Just because the out come is expected some of the time doesn’t make it not an accident.

Are you suggesting that people diving to 40m on an al80 should expect to get bent?

 

[CT-Rich]

The legality of driving while drunk is irrelevant. The drunk thinks he may get home safely, usually because his previous instances did not result in an accident. The legal issue is about dissuading people from trying.

Analyzing the the planning of the dive and its execution would be interesting and instructional. Unfortunately, we have very limited information about this incident. But having had it dumped in the popular press, we might as well dig around a bit.

Sadly, this guy may have become a much better diver/instructor as a result of his injury and we keep picking at the scab...

 

[KenGordon]

Are you suggesting that people diving to 40m on an al80 should expect to get bent?

Now and again, yes. I am not saying that the probability on a single dive is > 0.5 but it is higher than for a shallower dive.

That is quite deep and so uptake of nitrogen is high and fast. If they have an issue, which is more likely due to narcosis, and head directly to the surface they will have very high oversaturation and so a higher chance of a bend.

That deeper is more dangerous is supported eg here https://pdfs.semanticscholar.org/6c33/f24a077da9247fb8d43e4c5982808f7fe21e.pdf

And here is a plan to illustrate that it is enough gas, even at 20l/minute.

Depth Stop Run Mix pO2 EAD

Des 40 - 2 21 - -
Lvl 40 13 15 21 1.04 40
Asc 6 - 18 21 - -
Asc 5 - 18 21 - -
Stp 5 3:30 22 21 0.31 5
Sfc - - 23 21 - -

Dive # 1, ZHL-C+GF 100/100
Elevation = 0 m
CNS = 6%
OTU's = 17
Decozone start = 26 m
Gas density = 6.0g/l
Gas 21 = 1783 ltr.