UW narcosis monitoring...do you use it?

[lamont]

if i'm below 80-90 fsw, i'm going to be narc'd. i don't see a whole lot of benefit in testing it, since i think all it'd show at best was how well i was learning how to do the test while narc'd.

 

[ShakaZulu]

I like that idea, I normally start counting backward from 10-0.........especially when I start to check my instruments without noticing what they are telling me, got to love the sound of those bubbles.

 

[pilot fish]

When I first started diving I was tauhgt "the old narcosis check": you flash any number of fingers at your buddy and he (as fast as he can) shows you the same number of fingers plus 1.

Alot of divers don't use this method or haven't heard of it. Do you find it usefull? It doesn't work well with mits and everyone likes to give you one finger back (the middle one), but, even when diving with NITROX (or for more advanced divers TRIMIX with a realitively shallow EAD), I think it's important to keep track of how impaired you and your buddy may be. I don't feel it's ok to say, "well were diving with Nitrox at 90' so there's no need to even think about narcosis.

I have a few shipwrecks that I dive over and over, somtimes I feel narced, sometimes I don't. I don't think this is just me noticing it sometimes either, because in observing my buddy sometimes he seems a little off and sometimes he looks fine (when you dive with someone alot, it's easy to pick up on even small changes associated with narcosis).

So, that's what worries me about narcosis, in my limited experience, I can't predict it. For example, if I go out tonight and have 4 beers there's not much chance I'm going to wake up the next morning half naked on my lawn. I have a pretty good idea how 4 beers will affect me. With narcosis I've had a lot of trouble pinning down why sometimes (on the same wreck,at the same depth) I feel fine while other times I'm imparied. Narcosis seems very complicated to me.

So, back to the original question, what do you think of the finger test and do you have any other ones (besides ripping off your buddy's mask at 100' and observing his reaction)?

You raise a good question: why do you get narc'd on one dive and not the other, both being the same depth, same site even, and about the same BT? Wish I knew.

In February 04 I dove the USS Duane in Key Largo. It was my first dive on that trip and it was to 105 ft, 25 minutes, water temp 73.* I have a faint memory of the top of the ship after we descended but remember NOTHING about this dive, not coming up, or safety stop . I assume I did one since I would have been told by the person I buddied with on that dive if I did not, I guess. When I go up on the boat I felt a bit sea sick after a few minutes, 3 to 5 ft chop. After a 1 hr SI I did the second dive on Molasses Reef, 29 ft 36 minutes, only because I felt I would be less tossed around down there than on the boat. I was right. So, why did I get narc'd on that dive and not on other dives at the same depth and approximate duration? NO clue.

It was not until aftert my second dive that I realized I could write nothing in my log about the first dive. I thought it was very strange I could recall NOTHING about this dive. I mentioned it to someone day or so later. They said you were narc'd. I remember NO SYMTOMS either, whatever. I just remember seeing the bridge of the Duane and thinking, gee this is cool, then nothing after that at all. Wierd.

 

[MikeFerrara]

I just shoot some helium in my tank and don't worry about counting fingers (even in base 2) or whatever we're talking about here.

 

[Seadeuce]

Courtesy of the late Rob Palmer, speaking at the National Dive Conference, Cork, Ireland, 1987

The best test for narcosis is to go to a depth that you know you will not be narced at.
Then take a few breaths of heliox.
You will then realise how narced you were.


Seadeuce

 

[GDI]

I do this type of testing "8 count" I call it. What ever number of fingers I hold up you have to respond with the number that will equal "8". I hold up five you come back with three. (I will never give you seven by the way) Keep in mind though that you are also subject to becoming narced. I also have them do other taskings such as confirm air supply to each team member at pre-determined depths and time intervals.

 

[String]

Finger test would be useless for me, in thick 7mm gloves or drygloves its near impossible to bend an individual finger to give a signal like that.

General rule is if the buddys one eye is looking left, the other right theyre narced

 

[String]

I have a faint memory of the top of the ship after we descended but remember NOTHING about this dive, not coming up, or safety stop .

Thats not narcosis which isnt like alcohol - its effects disappear once the partial pressure is reduced, ie you rise.

 

[pilot fish]

Thats not narcosis which isnt like alcohol - its effects disappear once the partial pressure is reduced, ie you rise.

I'm afraid to ask. :11:

 

[BigBoB]

It has been my experience (I believe) that hydration has had the most to do with narcosis at different levels. Does anyone agree?