The Water-Nose-Reflex is a reflex produced naturally by the body which takes place when cold water touches the nose. Then your breathing stops involuntarily for a short period of time. This protects you from drowning, because no water can reach your lungs by means of the breathing air. As a diver you should still practise subduing this reflex though. Together with your diving expert you will practice this during your beginners’ diving course.
Because if you lose your mask under water this reflex could prevent you from breathing. As such you could panic and forget the most important rule of diving:
Never hold your breath!
Otherwise there is a risk of suffering from a barotrauma.
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