Surely this summer many of us will come to mind the image of great cliffs, intense blue waters, and diving among colorful fish… More and more people decide to enter the world of diving and diving schools They spend their August on the coasts of half the world with small descents in calm waters and extensive security measures. But there are those who see in diving another form of connection with nature , for them much deeper and they jump into the sea with nothing more than their lungs and, at most, some fins or a balloon that allows them to quickly rise to the surface: they are those who practice sport apnea or free diving.
It is a discipline that has been perfected over the centuries by lung fishermen as they are loved in Japan – a group of Japanese women who are nicknamed mermaids because they have been diving into the frozen sea for more than 1,300 years to collect abalone and pearls -, the Bajau -a nomadic people living in the Philippines, Malaysia and Indonesia in Indonesia, capable of diving 13 minutes at 60 meters – or the Wayú in Colombia and Venezuela.
Being able to hold your breath for a long time descending to great depths is more a matter of mental relaxation than physical exercise. Good nutrition and hydration is also important , and training in environments that simulate the conditions of hypoxia and high hydrostatic pressure that we are going to find: the effect is that the gases are compressed and the volume of the lungs is reduced considerably. . In this way, the diver’s body adapts to decrease its heart rate between 10% and 25% to consume less oxygen. The spleen also plays an important role by releasing more red blood cells so that the necessary oxygen reaches vital organs such as the brain and heart, at the expense of the one destined for the extremities. Thus, the Bajau, for example, have a larger spleen, which gives them a certain advantage when diving.
Between seals and whales
But for outstanding freedivers we have marine mammals such as seals and whales, capable of holding their breath underwater for a long time. They are a species whose muscles have changed over millions of years of evolution to increase their oxygen storage capacity. Thus, the common seal spends 80% of its time underwater , it can dive for 30 minutes and even sleep underwater: its nervous system has a mechanism that “auto-offs” and prevents it from breathing when it is not advisable to do so. .
Among the seals we find the genus Mirounga or sea elephant. After a search of almost 300 specimens of adult females, it was determined that they were capable of diving more than 1.7 kilometers deep. Another marine species that spends three quarters of its time diving is the sperm whale. It does this mostly for food. It can dive for at least 45 minutes and reach depths of 100 kilometers where it manages to hunt giant squid, its favorite food.
For their part, researchers from the Woods Hole Oceanographic Institution (United States) used electronic tags to track the movements of Cuvier’s beaked whales ( Ziphius cavirostris ), a cetacean of the 21 existing species within the beaked whale family. Scientists discovered that they can dive almost two kilometers deep and stay underwater for a whopping 85 minutes . These characteristics make it very difficult to observe beaked whales out of the water, making them one of the most mysterious marine mammals .
Among human mammals, and although lung fishermen have been diving in different parts of the planet for centuries, there is a man who is considered the first freediver in history: the Greek sponge fisherman Yorgos Haggi Statti .
The first freediver
Its history began in 1911 when the Italian battleship Regina Margherita lost its anchor and mooring chain after a major storm off Pigadia Bay, Karpathos, a Greek island located between Crete and Rhodes. After several days trying to recover it, one of the three Italian Navy divers died due to a black out, the loss of consciousness caused by cerebral hypoxia that can appear at the end of a dive (it usually occurs in the last 10 meters before reaching the surface): the swimmer does not experience an urgent need to breathe and if no one assists him, he dies.
Then the captain summoned a group of sponge fishermen, including Yorgos. With a sickly and emaciated appearance, he assured that he could descend to the depth of 77 meters where the anchor was, and even more, and that he was able to hold his breath for seven minutes. In exchange, he asked for five pounds sterling and the permit to fish with dynamite. Before accepting, the captain ordered the doctors on board to put him through an examination. They wrote the following report: “Thoracic circumference: 92 centimeters; weight: 60 kilograms; height: 1.75 meters; pulmonary emphysema ”. Faced with such a prognosis, the doctors recommended to the captain that this man should not dive. Even so, Yorgos dived three times that day to a depth of 77 meters, located the anchor and tied a rope to retrieve it, becoming the first deep diver in history.
References:
Donald, I. (2013) Underwater foraging – Freediving for food, Createspace publishing
Severinsen, S. A. (2010) Breathology: The Art of Conscious Breathing, Idelson-Gnocchi Ltd.
