Fainting at the surface in freediving: causes and prevention

Shallowwater blackout is the most dangerous situation in freediving and is completely preventable.

What is superficial syncope

When ascending from the depths, the oxygen pressure in the lungs drops sharply, and when approaching the surface, it reaches a level that is not sufficient to maintain consciousness, so the diver suddenly loses consciousness.

Why does it occur at the surface and not in the depths

At depths, high pressure keeps the oxygen level sufficient. When ascending, the air expands and the pressure decreases, so the oxygen available to the brain decreases.

Factors that increase risk

• Frequent and rapid deep breathing before diving, hyperventilation
• Physical fatigue and little sleep
• Extreme hunger or lack of hydration
• Frequent diving without adequate rest

Complete prevention

Do not hyperventilate before diving
Two or three normal breaths are enough. Frequent, rapid deep breathing reduces carbon dioxide and makes you lose consciousness.

Guardian Partner
Your partner should watch your face as soon as you surface and be ready to help immediately.

What to do if someone faints

• Keep him afloat with his head out of the water
• Call Help
• Initiate artificial respiration if he does not breathe on his own

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Make the rule of never diving alone the first and last rule of every dive.