The intoxication of the deep

Take a deep breath and dive... headlong into the fascinating sport of free-diving!
The records for this extreme sport are simply amazing, with some free-divers reaching a depth of 214 metres and holding their breath for up to 11 minutes 35 seconds. An excessively long time in the depths of the seas, during which the free-diver’s heart rate can be divided by three. The phenomenon is known as bradycardia, a slowdown in the heart rate, brought about here by water pressure, and one which was of great interest to Jacques Mayol, the first man to free dive to a depth of 100 metres on 23 November 1976 off the coast of the island of Elba.

Does the name Mayol perhaps sound vaguely familiar? This is probably because he was the inspiration for Jean-Marc Barr’s character in The Big Blue by Luc Besson. This Frenchman also displayed a passion for yoga and in particular was fascinated by yogis able to hold their breath for more than twenty minutes. In his book Homo Delphinus en 1987 (published by Editions Glenat), he described his meeting with them, the science of breathing (pranayama) and the idea from Indian philosophy that breath governs both a person’s physical and mental life.

As in yoga, mastering your breathing is one of the key aspects of free-diving. Before diving, each time the French record breaker would engage in lengthy meditation exercises. Today’s professionals also stress the need to learn different ways of filling your body with air, to be particularly attentive to movements of your diaphragm and to calm your heart rate before going underwater. “You have to learn to breathe all over again, to be able to hold your breath” explained Umberto Pelizzari, a sort of spiritual heir to Mayol, who smashed the Frenchman’s records in the 1990s.

With numerous books and films to his name, the Italian also insists on the absolute need for in-depth preparation for free-diving in the sea, referred to as “constant weight free-diving”, contrary to the “static” and “dynamic” categories, which take place in swimming pools. Because as you plunge down into the depths, numerous physiological phenomena related to the water pressure can occur. To begin with, it affects the eardrums and must be compensated for using the Valsalva manoeuvre, a small breathing exercise involving pinching the nose, making it possible to balance the pressure between the outer and middle ear thanks to the circulation of air in the Eustachian tube.

Next, the pressure increases over the whole body at a rate of 1 additional bar every 10 metres. You have to accept it without fighting it, remaining relaxed and "zen" like a yogi. Especially as the “cork” effect, which keeps the body near the surface at the beginning, starts to diminish at a depth of around 12 metres underwater. And the descent quickly accelerates. This “freefall” experience is absolutely amazing when the free-diver really lets go. The increased pressure can modify the blood circulation and the dissolution of gas in the diver’s veins such as nitrogen, which occurs more quickly between 30 and 40 metres, producing a moment of euphoria similar to intoxication... before recovering and resurfacing quickly to discover his time!