Scared of Nitrogen Narcosis

[Lobzilla]

The fact that you're concerned about it, heck, that you even know about it, make your chances of having to deal with it quite negligible. The people that run into problems with it are either stupid or have a macho complex that leads them to believe that it only happens to other people. Worrying, as long as it is not excessive or controlling, is a self-defense mechanism that keeps you sharp and helps you ensure that you do things right. Dive on!

Very true!

There is another important trait that SoccerJeni has shown by asking about the significance of Narc rather than just freaking out and throwing her scuba gear in the corner:

Think and analyze before you act!

When something startles us we have the tendency to 'just do something'. Even in situations where we need to act quickly we cannot ever omit the step of understanding what we are really dealing with.

Rebreather divers like CaveDiver are keenly aware that hastily pushing the wrong button will be the last mistake you make.

But even in more forgiving environments it is crucial to assess "What problem am I dealing with?" and then and only then "What am I going to do about it?"

 

[boulderjohn]

I might get my first chance to experience it this weekend...I'll be watching out for it!

The odds are that no matter how hard you look for it, you won't notice anything.

Many people argue (incorrectly) that even though they have many dives at depths greater than 100 feet, they have never been narced. They argue that because the degree to which they are impaired is such that their impairment actually masks their ability to perceive it. It is much like the person who has a couple of drinks and insists he is perfectly fine to drive. In both cases everything will usually go well, and both situations will end up just fine, unless, of course, something happens that requires that person's faculties to be fully unimpaired.

If I did not know better, I would be one of those saying he has never been narced, even though I have frequently dived at depths that would indicate that I should be. That is because I have never felt anything out of the ordinary during those dives. The reason I know I have been narced is that on a couple of occasions I had unusual things happen that made me realize I was not thinking at peak capacity. I have also realized after dives that I did not have clear memories of some tings. For example, on one very deep dive into the hold of a ship, I was right next to a videographer the entire time, but the video shows things I have no memory of seeing.

So, if you do a dive to normally recreational depths on either air or nitrox, the odds are very great that you will not feel anything out of the ordinary.

 

[DaMaDo]

Hmm, I wonder if the feeling is like in a decompression chamber. I went through USAF pilot training and in the chamber they take us to 24,000 feet to suffer hypoxia (half the atmosphere is below 18,000). Most people don't notice (and might not remember) so they take a video to show your decreased mental ability.

The only reason I noticed something was wrong was because I was given a baby toy where it's a ball with holes cut out into shapes and you need to fit the square in the square, triangle in the triangle etc. After not being able to find the square at all, I decided something was wrong and turned on the 100% O2. Without that "test" I probably would not have known better. I'm counting on having something similar to show this during my deep AOW.

 

[boulderjohn]

Hmm, I wonder if the feeling is like in a decompression chamber. I went through USAF pilot training and in the chamber they take us to 24,000 feet to suffer hypoxia (half the atmosphere is below 18,000). Most people don't notice (and might not remember) so they take a video to show your decreased mental ability.

Narcosis has indeed been tested and demonstrated in a chamber. Someone once posted a video showing such a demonstration. The star of the video, as I recall, was a woman who apparently was very staid and dismissive of narcosis. In the video she is, well, less than staid and is probably not as dismissive as before.

 

[SoccerJeni]

Hmm, I wonder if the feeling is like in a decompression chamber. I went through USAF pilot training and in the chamber they take us to 24,000 feet to suffer hypoxia (half the atmosphere is below 18,000). Most people don't notice (and might not remember) so they take a video to show your decreased mental ability.

The only reason I noticed something was wrong was because I was given a baby toy where it's a ball with holes cut out into shapes and you need to fit the square in the square, triangle in the triangle etc. After not being able to find the square at all, I decided something was wrong and turned on the 100% O2. Without that "test" I probably would not have known better. I'm counting on having something similar to show this during my deep AOW.

Come back and post about your experience...I want to see what happens. Please

 

[Lobzilla]

Hmm, I wonder if the feeling is like in a decompression chamber. I went through USAF pilot training and in the chamber they take us to 24,000 feet to suffer hypoxia (half the atmosphere is below 18,000). Most people don't notice (and might not remember) so they take a video to show your decreased mental ability.

The only reason I noticed something was wrong was because I was given a baby toy where it's a ball with holes cut out into shapes and you need to fit the square in the square, triangle in the triangle etc. After not being able to find the square at all, I decided something was wrong and turned on the 100% O2. Without that "test" I probably would not have known better. I'm counting on having something similar to show this during my deep AOW.

I also did the high-altitude chamber with exactly the same results. But hypoxia also got to me when flying much lower like around 9000 MSL at night with a high workload and little sleep before. Then, on a different day, you go to 12000 MSL and things are fine for much longer than the FAA allows (30 minutes).

A similar challenge exists with narcosis. At extreme depth, everyone is measurably narced. But if you repeat the test at shallower depth some people are still narced silly while otheres are not - at least not on that day.

Since the baby toy is not very practical underwater and a little embarassing in a cockpit, I do simple math calculations. Divide the PSI by the dive time or depth. Calculate the other two courses of a triangle from your current course. Something that you can do easily on the surface. If you cannot figure out anymore how to even approch these tasks let alone solve them it is time to turn.