An age-old question: ways to 60m.

[LFMarm]

There is risk in any type of diving (as well as most other human activities) but not all risks are the same:

• Tec diving is riskier than rec diving because it involves dives with higher exposure (depth, time, overhead) that require decompression and navigation procedures and often has mixes to safely return to the surface, ie more complex and hence with higher risk. This risk can be managed (not eliminated) with proper training, equipment, and procedures.
• Deep diving with wrong gases (eg deep air) is riskier than shallow diving or deep diving with proper mixes because of physiology and physics — this is why it’s frowned upon based on the last 50 years of research. It cannot be mitigated. It varies between individuals based on their own physiology and fitness.
• CC diving is more complex than OC hence could be more risky, however in my opinion is less risky in highly complex dives (very deep, overhead) because it gives more time which is critical for problem solving.

It’s very easy to mix and match all these different types of risk and try to justify one with another but we should acknowledge what is an objective risk and how/if can be mitigated.

 

[scubaozy]

The is risk in any type of diving (as well as most other human activities) but not all risks are the same:

- tec diving is riskier than rec diving because it involves dives with higher exposure (depth, time, overhead) that require decompression and navigation procedures and often has mixes to safely return to the surface, ie more complex and hence with higher risk. This risk can be managed (not eliminated) with proper training, equipment, and procedures.

- deep diving with wrong gases (eg deep air) is riskier than shallow diving or deep diving with proper mixes because of physiology and physics — this is why it’s frowned upon based on the last 50 years of research. It cannot be mitigated. It varies between individuals based on their own physiology and fitness.

- CC diving is more complex than OC hence could be more risky, however in my opinion is less risky in highly complex dives (very deep, overhead) because it gives more time which is critical for problem solving.

It’s very easy to mix and match all these different types or risks and try to justify one with another but we should acknowledge what is an objective risk and how/if can be mitigated.

According to your statements, if I dived deep on but not too complex, I might be safer with air than ccr but disadvantage is people will look down on me?

 

[LFMarm]

According to your statements, if I dived deep on but not too complex, I might be safer with air than ccr but disadvantage is people will look down on me?

That’s the mix and matching we should avoid. Deep with air goes against physics and physiology — never advisable.

 

[Wibble]

Agree, the rebreather is a killing instrument.

So, what are the safest killing instruments, I mean rebreathers, that is mixed gas CCRs?

CCRs with CE approval, that aren’t using unproven technologies, that are commonplace on boats and have plenty of great trainers.

 

[Kay Dee]

. The information on the dangers of deep air, including numerous fatality reports, were readily available to anyone who cared to look.

As are deaths on CCR today (which is not the same a me saying, which I dont, that air is better by any means). And I dont buy other posters' claims of 'shifting the goalpost' by bringing up CCR, as while it's the same playing field (underwater), there are no 'goalposts'. No one's trying to win game here. Or are they?

 

[J-Vo]

"Rebreather diving safety remains a critical issue, with incident rates similar to those of 10 years ago. Safety remains a work in progress in and for the technical diving community."

I can't believe I'm stepping into this.

When I listened to this talk during RF4, my 25 years of statistical analysis and engineering experience sent off blaring sirens of wrongness. The conclusion was based on having the same total number of incidents annually with no compensation for the increased denominator(we don't have firm numbers). There has been an exponential increase in the use of CCRs since RF3. I can only assume that the authors thought it wise to "scare" the public into continuing the trend toward improved safety.

 

[Kay Dee]

The problem I see is that the "deep air proponents" say it's basically ok to dive air, because helium is too expensive. Despite it being possible, it shouldn't be recommended.

Just to be clear, I am not, nor do I consider myself to be a deep air 'proponent', nor do I recommend it. And because helium was / is too expensive has never ever been my rational for a deep air dive. I have never done a deep air dive when helium was available (and I was cert'd to use it). I have actually paid big enough bucks to have G's of helium flown into G'canal (Solomons), etc, so money was not the reason for an air dive (nor a wish for the so-called narc 'buzz'). It was when certain situations arose when helium was simply not available, nor possible in advance to get it. So then one reverts to the last part of Yoda's famous saying which was "There is no try, there is only do or do not", and in those circumstance (no helium, and max depth 60/65m) it was, no question, I do did.

 

[Kay Dee]

One death on a deep air dive would be enough "statistics" to convince me that it's a bad idea.

Then what are your thoughts on CCR then?

 

[Kay Dee]

That's a very plausible observation and not a contradiction.

Pardon, buy would you care to clarify, as in all seriousness, even after reading the rest of your post, I am just not sure what you mean by this statement.

 

[Kay Dee]

My only point is that we shouldn't be recommending to others something which carries known, quantifiable, risks.

To key words, known and quantifiable. There are no longer too many unknown unknowns left (to quote Rummy) so people should be able to make decisions on an informed / fairly informed basis, these daze.

As for recommending people to do it (deep air), I don't! But I do try to present a balanced picture to show that it is not the gates of hell (for everyone) as many would have you believe to dive deep on air. My wife even did regular deep air dives (twins, multiple deco gases, etc) up to when she was mix cert'd, and even after (when no helium available, repeat ad infinitum) carrying multiple camera rigs at times (see below), and I had no qualms about it. As a matter of fact I was more 'worried' about her at 120m / 400ft on gas than at 60m on air.