Nitrogen Narcosis
Commonly called ‘getting narked’, nitrogen narcosis is a condition that occurs in scuba diving when a diver goes to a depth of 30 metres (100 feet) or deeper. It is caused by the increase in partial pressure of the nitrogen and as it dissolves into the blood, it can impair the conduction of nerve impulses. Not every will experience narcosis but the chances increase the deeper you go. The odds are a 1 in 52 chance at 30 metres to a 1 in 10 chance at 40 metres.
Also known as the ‘Martini Effect’ because the symptoms are very similar to being drunk, it’s commonly said that every breath is like having a shot of tequila. You might feel a false sense of security, disorientation, impaired complex reasoning and coordination, woozy, giddy or euphoric. Cold and stress can increase the chances and severity of the symptoms as can dehydration and a hangover. Never dive in the circumstances as Decompression Illness can be added as a potential problem as well.
Narcosis isn’t dangerous in itself, it’s what you do when you’re narked that can be a problem. The false sense of security can make you believe you can breathe underwater and that the fish next to you might be the one that needs a regulator. You might think that’s hilarious but it really has happened before, and not with a good result.
Another common problem is forgetting to check your air and depth so going over your decompression limit or running out of air can occur. Make sure that you always do your deep dive with an instructor and do your deep specialty to 40 metres so if you do experience it, your instructor can help you and you’ll know how it affects you. Once you’re certified, if you want to go deep then be sure to go with an experienced buddy and stay close to each (within arms length) when you’re deep.
The best way to avoid getting narked is to stay shallow, and if you do experience it at depth then ascending a few metres will alleviate the symptoms. For experienced divers it can be a lot of fun and the reason for going deep. For people who have never experienced it before it can be a little confusing and disorientating, hence the importance of having proper training before deep diving.
I did my deep specialty after my divemaster course and had never experienced narcosis at 30 metres. On the dive to 40 metres we settled on the sand and my instructor tapped his hand, asking for how much air I had. After 100 dives I should have known this but somehow it didn’t register and I just smiled and clapped, yay we were at 40. He shook his head and tapped his hand again… ok, maybe I missed something? I look at my dive buddy who gives the signals for how much air he had and then it hit me. I checked my air and tried to give the signal but my hands were more interesting and I forgot how much air I had. I check again, same thing. I have to keep looking at my SPG while I give the signal and finally complete the task. My instructor clapped and I started giggling and did so all the way back up to 35 metres where the narcosis wore off and I realised what had just happened.
I’ve seen some crazy things when people have been narked and ended up in fits of giggles under the water. One guy thought he was on a fish highway and started directing fish traffic. Another guy dug a hole in the sand to try and get his computer to register deeper than anyone else on the dive. I saw a little piece of coral dancing and singing Phil Collins. Can it get any stranger than that?
So how do divers avoid narcosis in technical diving? By reducing the amount of nitrogen in the mix and adding helium. This can get very expensive and not for everyone so stay at 30 metres or less to avoid any problems. Remember to always have proper training and a good buddy before attempting any deep dives. Always ascend a few metres if you get narked and the symptoms will go away. Do you have any funny narcosis stories you want to share? If so, drop us a line.
(By Kelly Luckman)
