Deep Diving and Nitrogen Narcosis

What may happen to us in the deep?

During our training, as early as our Open Water Course,we are made aware of the risks that come with deep water diving. It may not only be ourselves, as divers that experience problems in the deep, it might be malfunctioning equipment, ill health or even nitrogen narcosis. Some real, potential threats can be dealt with when we are all aware of what happens to ourselves when deep diving.

Certification Level and Insurance:

Do not dive deeper than you are trained. Remember, if you dive to a depth deeper than your certification level, your diving insurance coverage will probably become invalid. Even if you purchased a diving insurance which states you are covered to 40 m, if you do not have the qualifications to dive to 40 m, they will more than likely not pay! If you wish to dive deep, then take your deep diver course and learn to be prepared, while diving safely with an Instructor.

Your Buddy:

If you are a newcomer to deep diving below 30 m, go with a Buddy that you know well and who you trust. This must be someone who has deep diver training to 40 m, this rule also applies to to yourself! A good rule is to dive together, and stay together. Dive the plan that you agreed upon before entering the water. Plan scheduled pressure gauge and depth checks with each other. When communicating underwater, look your buddy in the eye, often an experienced diver can see things from facial expressions. If your response is slow or muddled, this is often a sign of nitrogen narcosis. In this situation ascend to a shallower depth, wait and see if the symptoms disappear, end the dive if necessary.

Your Dive Plan:

When we plan a deep dive, we must take into account our air consumption at depth. Your buddy’s air consumption is also critical to making your plans. Make sure you have the appropriate suit for protection against cooler water at depth. A dive computer is a must, each diver having their own – no sharing of instruments. When we are in deep water, believe what your instruments are telling you, this is vital for a safe dive. Keep your plan simple and safe.

Scuba Equipment:

When we plan a deep dive, we must take into account our air consumption at depth. Your buddy’s air consumption is also critical to making your plans. Make sure you have the appropriate suit for protection against cooler water at depth. A dive computer is a must, each diver having their own – no sharing of instruments. When we are in deep water, believe what your instruments are telling you, this is vital for a safe dive. Keep your plan simple and safe.

Be Well Rested and Physically Prepared:

When we plan a deep dive, we must take into account our air consumption at depth. Your buddy’s air consumption is also critical to making your plans. Make sure you have the appropriate suit for protection against cooler water at depth. A dive computer is a must, each diver having their own – no sharing of instruments. When we are in deep water, believe what your instruments are telling you, this is vital for a safe dive. Keep your plan simple and safe

Expect it will happen:

If we plan to dive below 30 m, expect that nitrogen narcosis will probably happen. If you prepare yourself for these symptoms, monitor yourself and your buddy, you will be able to spot signs and symptoms quickly. If we learn and know about these symptoms, it is easier to avoid mistakes and emergencies.

Breathing:

Breath normally during your deep dive. Don’t over exert yourself, this will result in shallow breathing, causing you not to empty your lungs properly. Re-breathing your carbon dioxide-filled gas will reduce the intake of oxygen and increase your levels of carbon dioxide.

Emergency Drill and Know-how:

Make sure you have emergency oxygen in place and have emergency contact numbers available. A mobile signal should also be checked out, sometimes these can be poor in remote areas. Run through, or practice if necessary your ability in rescue skills. Remember, in stressfull situations things lead very quickly from one thing to something bigger. Practice sharing air and keep your ability to help someone in/out of the water fresh in your mind. While doing your Buddy Check (do not skip this), be familiar where weights are stored, inflate and deflate buttons are located and check how the alternate air source is configured. Another tip: locate the quick release dump valves on your Buddies BCD.

Nitrogen Narcosis:

This weird disposition can cause all sorts of interesting and alarming situations. Some divers report they hear fish singing to them, some have a feeling of being drunk and not in control of their actions. Others have short-term memory loss. These divers tend to forget things, for example – why they are down there, how their equipment works or unable to read pressure gauges correctly. Symptoms and signs vary from diver to diver. So, what happens to us down there when we become ‘narked’?

What is Nitrogen Narcosis?

Also called inert gas narcosis. It is caused by breathing high partial pressures of concentrated nitrogen whilst breathing underwater. As we dive deeper the partial pressure of nitrogen increases, thus increasing the absorption of nitrogen into our bloodstream and on into our tissues. Often our nervous system slows down as nitrogen levels increase. This gives us the experience of having intoxicating effects that will seriously impair our judgement underwater.

Nitrogen narcosis is primarily caused through depth, but it is very difficult to predict what a safe depth is. Narcosis effects each diver individually, some feel symptoms at 30 m or even less, others experience these symptoms deeper than 30 m. This is one reason why the recreational diving depth limit ends at 40 m.

Symptoms of Nitrogen Narcosis:

It often begins with a slowing down of our brains awareness and our concentration. It is widely believed that nitrogen gas reacts with our fat tissues, which our brain is mostly consists of. We might experience an anaesthetic feeling, where we feel a reduction in our mental capacity to think straight. Multi-tasking, exact readings of computers and gauges may prove difficult, a feeling of nausea or euphoria may occur. Buoyancy, depth and awareness of your buddies whereabouts can prove difficult to monitor.

Narcosis can also cause a feeling of numbness. This can become a dangerous situation, it will reduce a diver’s perception to discomfort underwater, including turning cold and the mind and brain will not tell us that we are cold.

Hallucinations occur in more severe cases. Divers often do not check their instruments, or mistakenly check alternate air sources for their pressure gauges. It is important to know when divers behave in odd ways, this can quickly become a major incident. In such cases, ascend to shallower depths until the narcosis subsides, or end your dive.

Not only is nitrogen an inert gas, it has substantial effects on our brain and our mental state underwater. Some of us will experience euphoria underwater, while others will feel depressed and question why they are actually down there? Weird thoughts may go through your mind, your mind might wonder to all sorts of unpleasant thoughts. In both cases, divers should ascend slowly to a much shallower depth and wait until the feelings passes, if necessary end the dive. Do not attempt to return to the previous depth, stay shallow and stay safe.

No Side Effects:

Luckily for us divers, nitrogen narcosis is only temporary and has no long term effects. But only then, when the symptoms are recognized early and immediate action is taken to bring the diver up to a shallower depth. It is important for buddies, guides and instructors to recognize nitrogen narcosis symptoms and act accordingly. When ascending to a shallower depth, allow the diver time to adjust to the new surrounding pressure. Slowly the symptoms will subside and the diver will feel alright. Re-assess the situation and decide if you should abort the dive or carry on at a shallow depth. If you know you are susceptible to nitrogen narcosis then plan your dives shallower than 30 m. This is the simplest way to avoid becoming ‘narked’. Inform your fellow divers and buddies about your known problem, so they can be prepared to act accordingly.

Come and have fun on your PADI Deep Diver Specialty Course at Dive Smart Gozo!