Diving can be an incredibly fun experience. When done under the proper supervision and with the proper equipment, its an extremely safe and enjoyable experience. But, there are plenty of dangers involved for inexperienced divers who try to go beyond their limits. One of the main issues that can affect divers is nitrogen narcosis. In this article, we’re going to explain exactly what nitrogen narcosis is, what the symptoms are, and what you can do to prevent it.
What Is Nitrogen Narcosis?
Put simply, nitrogen narcosis is the build-up of nitrogen in the body. This buildup causes your body to experience a state of consciousness similar to drunkenness. In fact, many divers refer to nitrogen narcosis as the “martini effect”, due to the similarity to the feeling of being drunk.
Nitrogen narcosis is more properly known as gas narcosis in modern terminology. This is because we now know that other gasses can cause narcosis rather than just nitrogen. These are the inert gases, or the gasses we breath in and expel without using.
Nitrogen narcosis occurs when certain gases are under pressure. This compression makes the gas more soluble and easier to build up in your fatty tissues. The effects are typically delayed as the pressure of the air entering the lungs is the same as the atmospheric pressure outside of the tank. As you begin to descend deeper, the pressure in your body begins to catch up to the outside pressure. Within a few minutes, the air pressure in the blood passing through the brain begins to catch up.
This affects all divers differently. Some people seem to be more prone to the effects of nitrogen narcosis than others. There are instances where a diver may experience the effects on one dive but not the next, despite diving to similar levels on both dives. Other divers may have a more consistent experience with nitrogen narcosis. They experience the same feelings around the same depths every time they dive.
It is unknown exactly why this is. There are many different hypotheses that have been put forth to the exact causes of gas narcosis and why it affects people differently. But, there is still as of yet no concrete theory that has been found to cause this.
Symptoms Of Nitrogen Narcosis
The effects of nitrogen narcosis can come on slowly and be hard to recognize. One of the first symptoms is a mild euphoric feeling as if any anxiety or stress has been lifted. This usually begins to occur around 10m to 30m (33ft to 100ft). At this point, the effects are minimal and still may not be recognizable.
Next, divers may begin to feel some of the more noticeable effects. This can include a sense of overconfidence that can impair rational decision-making abilities. Some divers may experience slow reactions and the inability to coherently process what they are seeing and hearing. This usually begins between 30m and 50m (100ft to 165ft). At this point, it is possible for divers to begin making poor decisions due to the effects.
At 50m to 70m (165ft to 230ft), the effects of nitrogen narcosis can become extreme. At these depths, hallucinations can occur along with extreme sleepiness and impaired judgment. Many people who have experienced nitrogen narcosis at this depth have reported feeling confused. Some have reported a lack of recognition of their surroundings and the inability to remember things easily. Response times are also severely impacted at this point causing divers to improperly react to the situation.
Next, a sense of stupefaction can occur. This is where the diver experiences a feeling of extreme stupor, quite similar to being extremely drunk before the point of passing out. This usually occurs between the depths of 70m and 90m (230ft to 300ft). Memory at this point is severely impacted and response times are critically slow.
After 90m (300ft) the effects of nitrogen narcosis become the most extreme. Hallucinations can become quite extreme at this depth. Divers can experience swings between manic and depressive states. If left unchecked, the diver will eventually pass out. It is at this point that nitrogen narcosis can become fatal.
One of the most well-documented diving deaths occurred for this reason. Yuri Lipski, an Israeli dive instructor, met his fate at the bottom of the Dahab Blue Hole. This was the first recorded diver death in history. Lipski had a camera with him the entire time and documented his fatal descent. It is speculated that Yuri went too deep and began to succumb to the effects of nitrogen narcosis. His BCD blew out and he was unable to inflate it to ascend to the surface. The weight of his camera equipment helped to drag him down. Combined with the effects of nitrogen narcosis, he descended down to the seafloor where he eventually died.
What Are The Treatments For Nitrogen Narcosis?
Despite the rather harsh-sounding description of the effects of nitrogen narcosis, it is not in and of itself dangerous. When the symptoms are detected early enough, there is an easy treatment for nitrogen narcosis.
In order to treat nitrogen narcosis, a diver must ascend to a higher depth and let the gasses work themselves out. There is no lasting or permanent damage that nitrogen narcosis causes.
The primary danger from nitrogen narcosis comes when a diver fails to detect the symptoms and proceeds to descend further. This increases the effects of nitrogen narcosis and can lead to poor decision making. It is here that nitrogen narcosis can become fatal. There have been stories of divers removing their regulators and drowning. Others have become lost in cave systems and eventually run out of air.
The most important thing is that you know the symptoms and have them memorized. Nitrogen narcosis can affect divers at any depth. But, the symptoms typically don’t become noticeable until past 30m (100ft). At this point, if you are experiencing symptoms of nitrogen narcosis, immediately alert your dive partner. Your dive partner can help you ascend to a safe depth until the effects have worn off.
Stay at this depth until all of the effects have completely worn off. If you and your dive partner both feel comfortable, you can proceed with the dive. But, if you have any doubts about your ability to finish the dive safely, do not be afraid to call it off and come back another day.
Remember, no dive site on the planet is worth your life. Almost all diving deaths are entirely preventable and could have been avoided had better decisions been made. Don’t become one of the statistics in the Divers Alert Network annual reports.
How Do You Avoid Nitrogen Narcosis?
Unfortunately, nitrogen narcosis is an unavoidable part of diving. There is no way that you can prevent it. Especially, when diving with regular air. There are a few methods of diving which have been created to lessen the chances of nitrogen narcosis at depth. This involves the use of helium enriched air such as Trimix or Heliox.
Mixed gas diving is only for properly trained and certified divers as it comes with its own set of risks including oxygen toxicity. For the everyday recreational diver, the best way to mitigate the impact of nitrogen narcosis is to be aware of the symptoms and how to treat it.
There are a few narcosis tests that deepwater divers have come up with over the years. One of the most popular of these is the finger test. You will need to have this planned out with your dive partner ahead of time. The gist of the test is that as you descend deeper, you periodically check each other for impairment from nitrogen narcosis.
You do this by holding up a certain number of fingers. Your dive partner will then respond with a preselected number of fingers in return. Usually, this will be one more or one less than the number you held up. You will both have agreed on this beforehand. If the number of fingers is different than what you agreed on at the surface, it is a good idea to ascend and let any effects subside.
You will want to regularly perform these checks as you go deeper. This will help both you and your dive partner watch out for the signs of nitrogen narcosis. The earlier these are picked up and dealt with, the quicker you can get back to your dive.
What Is The Difference Between Nitrogen Narcosis And Decompression Sickness?
There is sometimes a bit of confusion between nitrogen narcosis and decompression sickness. The later is commonly referred to as ‘The Bends” and is much more severe and potentially fatal.
The most simple way to explain decompression sickness, before we get technical, is to think of a bottle of soda or cola. When you shake it up, it begins to form bubbles at the top. If you let it sit for a period of time, these bubbles will dissolve out and everything will be fine. But, if you try to open the soda or cola bottle immediately after shaking it, the soda will shoot out. This occurs as the pressure is being relieved from the high-pressure soda bottle to the lower pressure outside.
Think of your body as the bottle of soda and the air pressure the gas which builds up in your body when diving. As you go deeper, dissolved gases build up in your body at the same pressure you dove to. When you begin to ascend, these bubbles need a place to go. So, if you ascend too fast, the go where ever they can escape. This can include joints and other parts of the body.
But, if you ascend slowly, taking time to stop at certain pre-planned depths, the bubbles will slowly work themselves out. Just like the body of the soda. These pre-planned stops are called decompression stops and are required for divers who go past a certain depth.
Modern-day dive computers are built to take into account decompression stops and will alert you when and for how long you will need to stop. Always make sure you are heading these notifications. It is vital that you do not discount the safety stops. The only exception to this is if you are a highly trained technical diver and you have worked out specific stops.
As a beginner with deep diving and technical diving, however, you should always remain on the conservative side. Always factor in enough air for safety stops and always make sure you stay at the recommended depth for the full length of the stop.
Nitrogen narcosis is a serious issue that all divers must be aware of. Unfortunately, divers have died needlessly due to the effects of nitrogen narcosis. But, it doesn’t have to be you. As long as you plan accordingly for every dive you go on and don’t stray too far off your plan, you will be fine. Remember, nitrogen narcosis itself is harmless. There are no long term effects and it dissipates in a matter of minutes. The problems arise when people don’t recognize the symptoms. Don’t be one of those people.
Do you have any previous experience with nitrogen narcosis? Let us know your story in the comments section. We are always on the lookout for divers who can share their experiences. You never know when your experience could help out one of your fellow divers.