Scuba Diving

What Are the Dangers of Scuba Diving?

First of all, you can relax knowing that there is only 1 diving accident for 10 000 diving! However, diving must be done with prudence. Beginners or skilled diver, need to be aware of issues that can happen while diving. No matter which level you are, you can ask yourself some questions like “What happen if I go up to quickly?”, “I suffer from sinusitis, can I dive?”, “How can we solve this problem?” You must learn to prevent those issues in order to resolve them.

Risk of decompression sickness

Decompression sickness

Decompression is the reduction of pressure experienced by the body while diving. When you dive, you discover that the pressure is more important than the one on land. Under water, the deeper and the longer you dive, the bigger azote’s concentration is. Thus, Azote in the lungs will be dissolve in blood. By breathing and by respecting decompression stops, we evacuate this azote. That way, “degassing” is done correctly. When decompression stops aren’t respected (number or duration), the diver can have decompression sickness because the body doesn’t have enough time to eliminate the azote in the body. This lead to severe injuries and must be absolutely avoid. After diving, you shouldn’t take the plane before 24h. The azote in the body won’t have the time to evacuate because the difference between pressure will be too big. Gas embolism is very dangerous! These small gas bubbles in the blood can cause death. If you dive during 2 hours and not too deep, you can take the plane 12h after. To know more about it, read our article about taking the plane and diving.

How can we prevent this risk?

To avoid this risk, you need to respect carefully decompression stop and their duration.  Don’t smoke 8 hours or 12 hours before diving. Moreover, you really should reduce your smoking habit during your diving trip.

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Different kind of barotrauma

Sinus barotrauma

This barotrauma is linked to the difference of pressure between the exterior one and the one in nasal cavity. Indeed, when there is a “blockage” between sinuses and the latter, the diver will feel headache and will even have nosebleeds.

How can we prevent this risk?

Avoid diving when you have a cold. A salt water flush can help you.

Otic barotrauma

The rookie diver can often have the otic barotrauma. This kind can appear while you go down or you go up. In the depths, the pressure isn’t the same and this will affect your eardrum. If there is no rebalancing, the diver will feel violent pain in the ear and will even faint out. This can also happen when you go up.

How can we prevent this risk?

To avoid this imbalance, the diver can pinch his nose and blow or simulate a yawn (Valsalva method). If the diver still feels the pain, stop immediately the descent and go up of few meters, then try again to go down. If this happen during the go up, you need to do the reverse process: go down of few meters and then you can continue to go up. You can also do jaw movements.

Lung barotrauma

One of the barotrauma which happen the most to rookie divers. The difference of pressure leads to a variation of the air quantity. This phenomenon happens in the first 10 meters after the surface. The diver needs to exhale more than inhale when he comes close to the surface. This barotrauma doesn’t depend on the duration of diving. When the diver goes up, pressure decreases and gas quantity in lungs increases. If the diver goes up slowly, the excess of gas will be evacuated like it should be. However, if the diver goes up too quickly, the gas won’t have the time to evacuate and it will distend the alveolus in the lungs. This leads to the cracking of alveolus, bronchus, pleura and gas embolism (small gas bubbles in blood circulation). The diver will feel a strong pain in the chest and will spit blood.

How can we prevent this risk?

You need to call emergency services as soon as possible and supply oxygen to him. Respect the rule to always be under the instructor while going up or above him during the descent. The instructor can also remind to everyone to not hold his breath and that the diver needs to exhale more when going up. Be extremely careful because barotrauma can lead to fainting and drowning. To avoid drowning, never dive alone!

Teeth barotrauma

Be careful with bad teeth! Tooth decay for instance can lead to air pocket which creates a teeth barotrauma.

How can we prevent this risk?

Your teeth need to be healthy. An annual visit to the dentist is highly recommended.

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Biochemical accidents


Called also depths drunkenness. The diver can feel euphoric and his ability to think is reduced thus he can easily forget safety rules. It is linked to increase of azote. This phenomenon can appear at 30 meters, it’s a recurring problem at 60 meters and once you reached 90 meters, fainting can happen. Some people are more sensitive to nitrogen narcosisthan others: it depends on the depth, physical shape, fatigue, etc. Azote operates on nervous system and leads to odd behaviour. For instance, a diver can go up to quickly which will lead to decompression sickness.

How can we prevent this risk?

To avoid narcosis,the diver needs to go up in order to reduce blood pressure. If you haven’t dive in a while, you can also do a readaptation dive. Also, after reaching 30 meters of depths, you can go down slowly. If you are tired, don’t dive too deeply or too long. You can also use a different gas like Nitrix or Trimix which permits to reduce arterial pressure. Narcosis is boosted by a bad way of life: don’t drink alcohol before diving, avoid taking some medicine or to be anxious.

Oxygen and carbon monoxide poisoning

at depths, air has a bigger impact on the organism than on the land. Yet at a certain amount, oxygen and carbon monoxide are toxic. This can happen due to a bad filling of the bottles, thus the rate of these gas is too high. It gives you headache, sweat and nausea. Be careful not smoking 8 hours or 12 hours before diving. Tabaco contains carbon monoxide which help this kind of accident and decompression sickness.

How can we prevent this risk ?

Respect imperatively the rules for filling the bottles!

Shortness of breath

Shortness of breath or hypercapnia is due to an excess of carbon dioxide. The reasons can be external (pollution, dead space of tuba, etc.) or internal (physical effort, bad exhale, cold temperature). Depending on pressure, the symptoms can be a small shortness of breath, headaches more or less painful, feeling of tightening or suffocation, fainting and can even lead to death in very rare cases.

How can we prevent this risk?

If you have a shortness of breath, tell other divers. Don’t do any physical effort, catch your breath and if the symptoms keep going, you must go up slowly with another diver. Also, you can extend decompression stops.

Physical weaknesses

Back problem

The weight of diving equipment can be an issue if you have back problem like a herniated disc. Then, your doctor’s recommendation applies also at scuba diving.

How can we prevent this risk?

To avoid any pain linked to the weight of the bottle, you can put your equipment on when you are in the water. You can ask your instructor for help.


It’s a decrease of body temperature below average. This can happen when the diver doesn’t wear the good diving suit. Hypothermia can lead to diving accident like decompression sickness.

How can we prevent this risk?

Wear the good diving suit! You need to wear the good diving suit depending on your kind of diving. You can also wear a thick hood. Remind that a diver loses 80% of body warm by the head.

Diving must be done with safety but brings a lot of pleasure for the diver. Also, don’t forget that these accidents and incidents are rare and shouldn’t discourage you for diving.

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