Diving Deeper

[Lost Yooper]

I'm going to try and finish opening up a can of worms. The issue of O2 narcosis is a good one, and I need an update of the latest scientific info. I will be posting this subject on Dr. Deco's section.

There's a bunch to this subject that might be of interest to some here. My understanding is that O2 is (theoretically) narcotic, but only after a PPO2 exceeding 1.6.

We'll see what the docs here have to say. There used to be significant disagreement among the science guys over this subject.

Mike

 

[Walter]

NOAA Diving Manual 15 - 3 "Initially it would seem logical that with reduced nitrogen in the breathing mix there would be reduced nitrogen narcosis at depth. Although this has not been adequately studied, oxygen's properties suggest that it can also be a narcotic gas under pressure. The result is that one should not expect a sigmificant change in narcosis when diving nitrox as compared to air."

HTH,

DSSW,

WWW™

 

[scubatexastony]

Syruss,

Before the days of wisdom, I hit 170 with 4 of my buddies. A planned dive to "set our mark". Old navy tables had 190 as a limit for 5 mins (I think I remember this right), and we were aware of the feelings of getting "stupid" at 130-150 where we had been several times before.

Like many have cautioned, the effects are different for each person and on any given day, but through continued and careful practice you can learn to cope and function in the 100 ft. range with no problems. AGAIN I SAY... ANY GIVEN DAY AND ALL DIVERS TO SOME DEGREE WILL HAVE SYMPTOMS.

now for the flagging of my kan't spel nuthin buddies..... you make me reel proud

dive safe, live long

STT

 

[DivingGal]

The only symptoms I've noticed when I've been narc'd (and known about it...) is that my actions seem to be slowed down. What I mean is, I know I'm doing an action (what ever pointing, checking a gauge etc), but where I know "normally" it fairly quick and deliberate it seems to me to be in slow-mo. That's when I signal to head up for a bit.

As for seeing mermaids/mermen... maybe that's not a bad thing - especially if as Butch says he's "never seen a mermaid not naked" (I can only dream it applies to mermen too hehehe)

 

[rstone]

I guess im more the exception, then the rule.. ive been on many deep dives and have never got narc'd, ive always been very aware of what is going on around me, and very alert, although ive never went deeper then 130'.

 

[Green_Manelishi]

rstone, with all due respect you HAVE been narced, you "just
didn't feel it" and that is its danger.

 

[UKPhil]

You might only notice youre narked when you hit a problem. When I did my AOW 'deep' dive to only 70' but in a cold quarry, it suddenly got cold and dark about 6 feet above the bottom which I hadn't expected. I didn't feel what I would have expected to be narcosis, but the way I reacted to the situation I was in (anxiety, slight feeling of panic and desire to ascend) makes me believe my reasoning was impaired. When I got back up to 30 feet the feeling had gone.

 

[rstone]

Originally posted by Green_Manelishi
rstone, with all due respect you HAVE been narced, you "just
didn't feel it" and that is its danger.

I guess it just depends how you define NARCED.

 

[Walter]

GM,

I think rstone has a valid point. It does depend on how you define terms. I'm willing to believe there is no measurable diminishment of rstone's mental abilities at any depth.

DSSW,

WWW™

 

[100days-a-year]

rstone....the point most make is that the apparent lack of obvious impaiment is the most dangerous part of narcosis.EVERY study done on the subject has shown that at depths of 100' or 30M ALL divers are impaired in motor and cognitive ability.However as pointed out there is wide tolerance differences between divers and even dives .Back when I got tri-mix cerified it was common to go thru the vestiges of a deep-air course to see the differences between 02/N and 02/He/N mixes.I regularly dive in 85-135' of water,I don't feel cheesy,but when a situation comes up that requires full concentration it is easy for me to see the difference.When I go deeper than that it's almost always on mix ,there are just no valid reasons to dive air deep.