PSAI Narcosis Management course - 73m on air

[DevonDiver]

/sigh As I have stated several times now, you can do levels 1-5, which is the actual course....They don't exceed 1.6 PPO2

No need to sigh. I don't think anyone is attacking levels 1-5. Although the same benefits could be achieved from conducting an Extended Range course...and that also brings new skills and certification.

IF you want/choose to do level 6/73m and get approval, you can

So, how did you get approval....given you relatively entry-level tech certification and the fact you aren't qualified to those depths?

Surely this course would be restricted to divers who are already certified to dive (trimix) to those depths...and would want to explore their preparedness for narcosis as a contingency (emergency bail-out onto air for CCR users?!?).

Everyone wants to jump on this course for doing 73m on air

Yes, understandably.....

And if you believe that narcosis can't be 'managed' don't take a course called narcosis management FFS

Is it like Santa...or the Easter Bunny.... it only comes if you believe in it?

 

[netmage]

What was your specific motivation for deep air vs. mix...?

 

[rjack321]

At level 5 (200ft/61m) you're still below the depth of "modern" extended range courses which typically limit at 180ft. Personally keeping track of my pressure and my buddies pressure under extreme narcosis doesn't even sound like diving. That just mechanicanized behavior.

 

[Rainer]

What was your specific motivation for deep air vs. mix...?

I assume the same as his instructors who prefer deep air over mix: nickel rocketry, ignorance, false bravado, penchant for being stoned, and possibly stupidity.

 

[amascuba]

I don't believe he was..... just the excessively deep, ox-tox dangerous, aspect of it.

Hal Watt's is a product of technical diving before mixed gases were available. In those day's people routinely pushed the envelope of deep air dives to 300+ feet. Rarely do you read reports of people having a toxing event. I've read more stories of people actually passing out due to extreme narcosis and drowning than having a toxing event. The exposures of elevated PPO2's are relatively short. You don't really see stories of toxing events until accelerated deco and mixed gases become available.

I think having an understanding of narcosis management is probably a good thing, but to practice it in your day to day diving as a necessity is probably not the wisest move in the book, especially since we have better tools for the job nowadays.

 

[DevonDiver]

I would expect reports to be rare also....technical deep diving into those ranges was a rare thing back then. The sample size was small.

I would be interested to read the statistics, if such numbers existed.

The one thing that experience and studies have taught us, as technical diving has evolved in the past 2-3 decades is that ppo2 must be respected. That is why the trend has been for lower and lower ppo2 limits.

 

[rjack321]

I would expect reports to be rare also....technical deep diving into those ranges was a rare thing back then. The sample size was small.

I would be interested to read the statistics, if such numbers existed.

The one thing that experience and studies have taught us, as technical diving has evolved in the past 2-3 decades is that ppo2 must be respected. That is why the trend has been for lower and lower ppo2 limits.

Read Exley's book "Caverns Measureless to Man". Toxing at 350+ft on air didn't seem to happen, I speculate to to the extreme CNS depression occurring from N2. The principle risk seemed to be passing out from the stupor.

 

[DevonDiver]

There is some logic to the CNS depression.....at extreme depth. At 73m?

 

[Tortuga68]

What was your specific motivation for deep air vs. mix...?

My instructor, who I respect enourmously due to what he has acheived in his diving career, suggested the course to me, as I was looking for something that would expand upon my existing deep decompression diving experience

As far as I'm concerned, the course delivered on it's promise. It gave me some tools to plan and execute deeper dives in the 40-60m range safely for myself and my team members. The 65m dive we did I was much more aware of myself, my team and my dive plan than on 50m dives I've done previously

I assume the same as his instructors who prefer deep air over mix: nickel rocketry, ignorance, false bravado, penchant for being stoned, and possibly stupidity.

Don't hold back, tell us what you really think. You know what they say about assumptions, and you're making some pretty bold ones given you don't know any of the people that you're so quick to judge

I think having an understanding of narcosis management is probably a good thing, but to practice it in your day to day diving as a necessity is probably not the wisest move in the book, especially since we have better tools for the job nowadays.

I agree - as I said earlier, the course is not about encouraging or certifiying divers to repeat the dives or depths of the course; it is about teaching skills to make a safe deep dive and deal with any narcotic effects as best as possible


I'm surprised that with all the knee-jerk bashing of going over 1.6 partial perssure, no-one has even bothered to ask what the run time was for the dive. FYI bottom time was 10 minutes, 5 of which was consumed with descent. So we spent a total of 5 minutes at 73/74m before commencing the ascent

 

[Tortuga68]

By the way personally I dont think you can learn to manage narcosis, kind of like the drunk driving analogy given above

I think one flaw in the 'drunk driving' analogy is that if you start to experience narcosis impairment, all you have to do is ascend to recover. Of course you need to be aware that you should ascend, that's something the course teaches you, to recognise and act accordingly

As far as not being able to manage narcosis... Are you in good physical condition? Did you get a good night's sleep? Did you hydrate yourself? Did you avoid alcohol for 24hrs prior to the dive? Did you avoid exertion prior to and during the descent? Have you planned your dive and discussed the plan with your team? In other words, are you mentally and physically prepared for the dive? Congratulations, you just took some steps towards managng your narcosis