Nitrogen Narcosis: Drugged in the Deep

Nitrogen narcosis; "rapture of the deep" or so Jacques Cousteau described it.

When we breathe air we’re basically breathing 21% oxygen and 79% nitrogen. Oxygen is used by the body for cellular respiration.

The body metabolizes oxygen. Nitrogen on the other hand is just filler. It doesn’t really do anything; at least, not on the surface anyway.

However once you start diving below 100 feet (30 meters) or so, nitrogen begins to act a lot like alcohol.

It inhibits nerve conduction and causes slowed reaction time, loss of manual dexterity, anxiety and in some cases giddiness and euphoria.

"Rapture of the Deep"

This giddiness and euphoria has earned narcosis the nickname “the rapture of the deep.” Jacque Cousteau once mentioned that he saw one of his divers offer his regulator to a fish so the fish could breathe.

While nitrogen narcosis can sound like fun, it presents a number of dangers to the diver that can be quite scary. Take my experience for example.

The first time I experienced narcosis, I was with three other divers and we planned to dive a wreck on a sandy flat bottom in about 130 feet (40 meters) saltwater. I was diving air and halfway through the dive I realized I was actually swimming away from the wreck staring at the sandy bottom, which was not that interesting, luckily I turned around, saw the wreck and returned.

Fortunately I was with other divers so I started to surface when they did. As I ascended my mind began to clear.

Fortunately the effects of nitrogen narcosis wear off as soon as you return to shallower depths. However if I wasn’t diving with other people, I could have stayed on the bottom for too long and risked decompression sickness. I might have even run out of air and 130 feet (40 meters) is a long way to go with no air.

How do you avoid Nitrogen Narcosis?

The key to avoiding narcosis is to be self aware.

You need to realize when something feels out of the ordinary so you can make the necessary adjustments. If you’re ever diving in the 80 to 130 foot (24 – 40 meter) range, make a conscious effort to know if you start to feel anxious, giddy, dizzy, or nauseous.

Each of these symptoms can be signs of nitrogen narcosis. If you start to feel any of these symptoms you should alert your dive buddy immediately and then slowly ascend 10 to 20 feet (3 – 6 meters) to see if your symptoms go away. If they don’t, ascend another 10 to 20 feet (3 – 6 meters) until they do. Once they symptoms go away, you’re free to resume your dive at your current depth.

Nitrogen narcosis can occur at different depths on different dives depending on the environmental conditions and your stress level. Take a tip from Jedi Master Obi-wan and “Always be mindful of your feelings.”

That little tip will go a long way to preventing nitrogen narcosis.

Return to Underwater Diving Equipment Home Page.

footer for Nitrogen Narcosis page