Underwater diving or scuba diving is a very popular extreme sport, which fascinates first of all by the possibility to see the amazing beauty of natural objects that you could not even imagine before. But as with any extreme activity, diving has its own nuances, which entail deadly dangers. Everyone knows that you can dive only after special training, as well as being in good health. Beginners and untrained swimmers diving can cause serious harm, up to and including death. But approaching responsibly to such an activity, all this can be avoided, most importantly, really well prepared. It happens that if you dive incorrectly, the mask strongly presses, or we can say sucks to the face, having a pressing effect on the soft tissues. The result is bleeding into the capillaries of the eyes and skin. Barotrauma is one of the most common injuries from improper diving techniques. These are injuries to internal organs that result from pressure differences. Barotraumas can be numerous. Barotrauma of the middle ear occurs mostly during the descent, and if you don't correct your technique when you feel discomfort in your ears, it can lead to a rupture of the eardrum. By the way, for a proper descent, diver courses teach a special technique of blowing air. If you have fillings in your teeth, then you may also be susceptible to dental barotrauma - when, again, if you break the rules of diving or surfacing, there is strong pressure on the dental nerve, which leads to severe pain. Most life-threatening are barotraumas of the intestinal tract or lung. In the first case, the expansion of the gas bubble in the GI tract can provoke severe abdominal pain or vomiting as a result of swallowing air. Barotrauma of the lung in the worst case leads to its rupture, gas embolism. The ingress of air bubbles into the blood can provoke visual impairment and general coordination, up to and including loss of consciousness, and in the worst cases it can be fatal. In most cases, such injuries occur when improperly surfacing - air in the lungs can not be withheld, but, unfortunately, many people forget about it. If the route is miscalculated or changed, there may not be enough oxygen. And when the air runs out, the diver will inevitably panic, which increases the likelihood of unconsciousness, and then lethality. The body loses heat in the water dozens of times faster than on land. Even in very warm water the possibility of hypothermia is high (in most cases it depends, of course, on the lack of a wetsuit). And here, as a consequence - rigor mortis, cramps, loss of consciousness. Many marine creatures are not happy with the appearance of unfamiliar creatures and begin to defend themselves in every way. Some are so tough that they can stick their poison even through the thick layer of your wetsuit. As in rivers, so in seas and oceans, there are currents. Some can carry you completely unnoticed far from the shore. If you use a wetsuit and flippers it will certainly be easier to stay in the water, but if you dive without equipment you'll need a lot more stamina to be able to get out of the current. Of course, in places specially fenced for diving, you are unlikely to meet fishing nets, but if you decide to go underwater in a wild body of water, there is a chance to get entangled in the posted traps for fish. Whether it's an ordinary boat or a jet ski, any noise underwater is perceived much worse than on land, so you simply may not hear the vessel above you. And the rest is clear - a sudden collision with an object moving at speed does not end well.