Course Outline

Nitrogen Narcosis

Many experienced divers have felt the effects of what has been called “rapture of the deep” or getting the “narks” at around 30 meters/100 feet. In many cases, mild nitrogen narcosis is a fairly harmless phenomenon. And as long as you are aware of its existence, you can manage its effects at the depths covered in the course. Narcosis develops primarily as the partial pressure of nitrogen increases; however, it’s thought that several other factors—fatigue, cold exposure, poor visibility, mental stress, high workload—can all contribute to the effects.

Signs of nitrogen narcosis can include the following:

  • Feeling a false sense of security
  • Exercising poor judgment
  • Becoming uncoordinated
  • Having euphoric feelings, fixations, and anxiety

All symptoms are similar to being drunk on alcohol. The onset of nitrogen narcosis varies from diver to diver and for each diver from day to day. Inadequate hydration and the use of some prescription and recreational drugs—among other things—can worsen symptoms.

What Should You Do When Nitrogen Narcosis Strikes?

Unlike the effects of alcohol, nitrogen narcosis can be “turned down” or “turned off” simply by ascending a few meters—maybe 3 meters/10 feet. So, the correct action if you feel a little “narced” is to get your buddy’s or dive professional’s attention. Slowly ascend until the feeling subsides while keeping an eye on your buddy or dive professional to make sure he or she is OK and is ascending with you.

As with getting drunk, there is a “funny side.” However, nitrogen narcosis should be taken seriously. Everyone reacts differently, and it is important you are on the lookout for symptoms in yourself and others. Always ascend if significant symptoms present themselves.

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