An age-old question: ways to 60m.

[Kay Dee]

It's hilarious that you think a slide from some random bottom-of-the-barrel training agency run by has-beens and never-has-beens strengthens your point. It's pontificating clowns like that who who make tech diving dangerous in the first place because they're presuming to teach complex subjects when they aren't even clear on the basics themselves. If you want anyone here to take you seriously you'll have to come up with something more convincing.

It's sad to see some of the "old timers" who are still innumerate and unclear on the basics...............................................You would understand this if you had ever been properly trained on

I learnt a long time ago that you can always cut someone some slack if they were born with, or into, holier than thou attitudes. But anyone who thinks their TTP's*, or their kit / method of diving is better than everyone else's, well.................you treat them with the disdain they deserve. Folks with those attitudes don't last a minute in many 'circles', or when out of their comfort zone.

*In this case training, techniques and procedures.

 

[lostsheep]

Same as anything else in life...

You can do everything right and get out of the water badly bent, or with a AGE, or have an IPE when you descend, or maybe it's just not your day and some ******* shark comes along and bites you.

There are always going to be residual risks that are related to the objective hazards.

Objective hazards are a natural part of the environment. They cannot be eliminated, and one must either:

• Not go into the environment where they exist, or
• Adhere to a procedure where safety from the hazard is assured.

Gas density and narcosis are objective hazards of breathing compressed gas under pressures, you're options are to not go in the environment or mitigate / eliminate the risk through correct gas selection.

Same as cave diving, no one is arguing for going cave diving without the right equipment and training, but people are fine taking the wrong equipment deep in the ocean because their perception of the risk is that it is inconsequential, or saying f it I can go to 60m with only AOW training. You can get away with cave diving on a single tank for a long time too...

I’m not arguing for deep air; narcosis and co2 retention are real. I’m just sick of the comparison to driving , it’s absurd.

If you all insist on on the driving comparison , at least compare it to a track day.

 

[flymolo]

What’s funny with all this, well not funny but laughable, is that you would think that before helium came along and became ‘widely’ accepted / used among ‘sport’ (dislike that word in the diving context) divers, that nothing deeper than the 40m Padi limit got dived / accomplished on air. I wonder what the northeast boys on the Doria, and the guys on the deeper south Florida wrecks, the early days in Asian waters and the South Pacific, and other locations around the world would think of that?

i imagine you'll find the majority of them have switched to trimix and ccr and are no longer diving deep air. that would be my guess at least

 

[Kay Dee]

i imagine you'll find the majority of them have switched to trimix and ccr and are no longer diving deep air. that would be my guess at least

Obviously, as did I. But for the umpteenth time, when the necessity arose I didnt hesitate to use air if thats all their was.

 

[flymolo]

Obviously, as did I. But for the umpteenth time, when the necessity arose I didnt hesitate to use air if thats all their was.

yeah i get it

 

[leadduck]

Gotta disagree (again) about your "didnt know any better". I certainly didn't know what I know now, but in 2000 I had been mixed gas diving 8 years and rebreather diving five, so I knew 'enough' to keep myself 'out of trouble'. Now I know even more, so am even more able / qualified to evaluate the risks.

And I gotta also say, that if anyone is deep OC diving (air or gas) and you have a problem with overbreathing your reg/s or gas density, then they must really really be second rate regs. In all my days, while I have overbreathed my CCR, I have never ever overbreathed an OC reg, never, and I have dived the world over on OC in a myriad of conditions (I used at various time top of the line Poseidon, Apeks and Scubapro). Again just saying, from personal experience.

The issue with gas density in deep air has nothing to do with overbreathing the regs. It's about the internal airway resistance within your lungs. At 60m, your lungs cannot achieve the same maximum SAC rate with air as with trimix, or with air at 30m. If high workload happens (planned or unexpected), your lungs cannot get rid of CO2 fast enough at 60m on air, no matter what reg you use. That's one of the things we didn't know in 2000.

 

[Centrals]

@Kay Dee
Still out looking for WWII wrecks without Empress and the Capt?

"There is always better gas than air"! I am flexible.

 

[CG43]

The issue with gas density in deep air has nothing to do with overbreathing the regs. It's about the internal airway resistance within your lungs. At 60m, your lungs cannot achieve the same maximum SAC rate with air as with trimix, or with air at 30m. If high workload happens (planned or unexpected), your lungs cannot get rid of CO2 fast enough at 60m on air, no matter what reg you use. That's one of the things we didn't know in 2000.

You are right with first , but you can read this in JYC book "the silent world" 1952 in chapter III "sunken ships" and chapter VIII "90 m deep" where he described there 90m , 93m and Maurice Fargues deadly 120m dive .
There is also a picture of the writing board on which Farques wrote something like his name before he drowned. That impressed me a lot as a young diver, why I only gradually and systematically increased my deep diving.
btw: Because we dove deep air, we were very well aware of the problem from our own experience and there were also scuba regs. that made the problem worse.

 

[CG43]

We feel comfortable because we have ways of taking virtually all of the risk out, to the extent that driving to the dive site is the deadliest part. Correct gas selection is one part of that but there are other aspects that go beyond what can be explained in a forum post. This is all covered in proper training courses.

I almost always find your posts very precise and informative. That's why I think technical diving suits you very well.
Unfortunately, in my experience, you're an exception because many divers only have a superficial understanding of more complex technology. A lot can be taught in courses, but how effective are such courses? This applies to both the practical use of the equipment and the theory. M25x2 valves are screwed into 3/4 NPS tanks, and divers aren't even able to understand how a two-stage regulator works.
Can technical diving be safe under such conditions? I can't imagine that.

 

[old frogman]

I almost always find your posts very precise and informative. That's why I think technical diving suits you very well.
Unfortunately, in my experience, you're an exception because many divers only have a superficial understanding of more complex technology. A lot can be taught in courses, but how effective are such courses? This applies to both the practical use of the equipment and the theory. M25x2 valves are screwed into 3/4 NPS tanks, and divers aren't even able to understand how a two-stage regulator works.
Can technical diving be safe under such conditions? I can't imagine that.

Super interesting point about questioning the effectiveness of courses. There is an old saying in aviation, "there are bold pilots and old pilots, but there are no old, bold pilots. The point is that personal traits will determine how safe a person will be underwater. This is regardless of the training agency, type of equipment used, gas selection, depth, etc.

Personal traits of good divers are as follows:
Low neuroticism - less prone to anxiety and negative emotions.
High conscientiousness - careful planning and adherence to plan during execution.
Introversion or low sensation-seeking - measured personalities make safer calls at depth.
High cognitive flexibility -ability to shift thought patterns quickly.
Strong internal monitoring - maintain a sharp sense of mental state to respond proactively in event of change of circumstances.
Decisiveness - Rapid decision-making ability.
Emotional regulation - remaining calm under stress.
Risk management - ability to accept calculated risks (in contrast to rule-based safety management).

These are personal traits one is born with. They can be enhanced through training but if you do not have them, training is not going to create them.