Most of us probably haven’t really studied narcosis since we were rooky divers, aside from the usual “narked” jokes we all make about mermaids and dolphins. So it seems like a good time to cover the subject in an easy to understand format.

I’ve recently carried out a little informal survey with many divers, and there seems to be no obvious indicator as to when or why it should occur. It just sometimes happens, but most often doesn’t.

Let’s answer some basic questions about Nitrogen Narcosis:

What is it?

Basically, nitrogen (which is inert when breathed on the surface) has a narcotic effect when breathed under pressure. As divers we all know this, and we know that our speed of thought and reaction is compromised by this effect when we are at depth. It’s something we compensate for, or should. But occasionally, sometimes at just 25 meters, it can strike much harder. Science tells us that factors such as fatigue, workload and dehydration can contribute, although the mini survey I did suggests there aren’t obvious factors like these.

What does it feel like?

Common descriptions are that you feel drunk, very light headed and / or euphoric. In my case I feel a “shimmer” as though a sudden strong current is moving my body sideways. At worst, divers can take off their weights, remove their regulators or bolt for the surface. At best, we just experience this strange sensation and recognize it for what it is.

What should we do about it?

First, control breathing, then ascend a few meters until the feeling passes. Try to explain to your buddy what you’re doing, so they stay with you. It usually passes as you ascend, and often doesn’t come back when you descend again. But if it does, you should abort the dive. If you see irrational behavior from your buddy, and suspect nitrogen narcosis, try to signal them to move up a little, but be cautious if you have to help, in case they decide you don’t need your regulator!

Summary

If you dive regularly and you dive deep, you will occasionally be narked from time to time. Learn to recognize the symptoms and to deal with them as advised above. To minimize the risks ensure you don’t dive when tired, don’t work too hard at depth and that you are always well hydrated before diving.

Comments

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