Getting narced.

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Originally posted by Heads Up


Hehe - been having a couple yourself by the looks of it, Doc!!

Jay! Jay! Jay! Jay! Jay!

Hadn't you noticed how the rest of us politely refrained from commenting on the obvious....

....apart from a few quite snickers....

:wink:
 
Guess Heads Up is to this post what the little girl was to the emperor in "The Emperor's New Clothes."

There's one in every bunch! :innocent: :innocent:

:boozer:
Ber :bunny:
 
Whoops!

Looks as though my spell checker went on strike!:wink:

It has been a tough day at the old lab.....:doctor:

Dr Deco
 
I`ve done a 35 metre dive in a quarry it was about 9 degrees c and viz dropped down to about 3 foot and my head went ! felt as if i was going round in circles under it clicked to turn my big touch on .
Done 40 metre dive good viz and about 14 degrees ,
done 50 metre head gone again with good viz but 6 degrees c temp .
Done a dive to 40 hesd clear dropped to 50 started to get narc then stayed there until faded a bit then dropped to 62 metre and had the same as at 50 m .
It`s like a drug the more you use it the more you get used to it ,
So if you do build up dives to say 35 metres you`ll find it may affect you less .
 
Originally posted by simon66
It`s like a drug the more you use it the more you get used to it ,
So if you do build up dives to say 35 metres you`ll find it may affect you less .

This is a common misconception. You will still be subject to the same levels of narcosis but your brain will be used to the effects while under the same conditions

A good analogy is alchohol - when you first start drinking, your tolerance (i.e. mental) is low - you drink for a while and you feel you can handle it better. Dr Deco correctly identified that:

Many individuals, for example, drive while intoxicated and believe that they are in full control of their faculties

While they are doing their normal 'driving' they feel in control and can navigate their way home. BUT - if someone were to step in front of their car, their reactions would be severly impaired by the alchohol and the result would probably be a catastrohpy. The anology follows into diving. You MAY become accustomed to the affects of narcosis because 99% of your dives will be without incident and therefore pass unnoticed (apart from you feeling that you have got use to the effects of narcosis) BUT should sometime happen that is unexpected, the narcosis may become overwhelming and make your judgement / reactions SEVERLY impaired. This is a law of physics and NOT something you can overcome through experince (IMHO)
 
I do not accept the alcohol analogy. There is almost no similarity. Objective tests conducted on automobile drivers show that one or two drinks of strong spirits actually results in faster reaction times and higher scores navigating the pylons. It's only when consumption exceeds two drinks that scores decline. I personally saw these tests conducted by the police in the DC area about 10 years ago. The results put an end to that particular PR event as I've heard no mention since.

Nitrogen affects a diver in a different way. At the two martini depth a diver is definitely impaired as can be shown by arranged tests such as puzzle solving and reaction times. Typically, the diver will otherwise not be aware of this impairment, as it is relatively slight.

Personally, I have found the following to be true. As mentioned by "100 days", handling and shooting of a speargun is impaired slightly at 130 feet. Same for use of a camera. At 200 feet, it requires concentration to handle and focus a camera. I do not use a gun at this depth as it could be dangerous. My personal limit is 260 feet where the world begins to distort and hallucinate. Frequently, I formed the impression that my fingers had become thick like fat sausages. There is a feeling of being out of control. Unlike alcohol, I never became sleepy or drowsy but it required the same level of willful control as if I had downed two or three water glasses of 100 proof hooch.

I can also state that drinking before diving, even one beer, exacerbates narcosis. This is subtle but can be noticed in the accuracy of using a speargun at moderate depths of 60-80 feet. So, at least in this way, there is some relationship or synergism between alcohol and nitrogen. There is no direct correlation of effects, however, as postulated by Cousteau and some others.
 
In Alaska last year I was known to dive VERY deep on air. The lady I was diving with also dove very deep on air. One day I decided to take the video camera and housing. That housing was only rated to 200 feet, so I was hesitant, but I wanted to see how narced I was.
It's unbelievable how narced I was past 200 fsw. Let's just say I won't be going below about 165 on air ever again.
Oddly enough, I did manifold shutdown drills and the times were only off by 20%, still well within all agency accepted standards.
After spending a few hundred deep air dives, I have one recommendation, since you are narced enough to not realize you are narced, what else slips your mind?
Just my input!:confused:
 

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