Breathing the air from cylinders, the South African Nuno Gomes reached 318.25 meters in June 2005. With only the air in his lungs, the record is held by the Belgian Patrick Musimu: in a single breath, he went to 209.6 meters ! However, despite having documented the dive on video, Musimu did not accept the presence of judges from the International Association for the Development of Freediving, the main organization of the sport, and, therefore, is not officially recognized as the record holder. The official mark of the Limitless category, which allows the use of a sled to speed up the descent (see the infographic on the side), is from the Austrian Herbert Nitsch – 172 meters. The great difficulty in deep dives, with or without a cylinder, is the pressure. At the surface, the pressure is 1 kilogram per cm2 (or 1 atmosphere), and under water it increases by 1 kilogram per cm2 every 10 meters – so at 200 meters it is 21 times greater than at the surface. What does that mean? For the apnea diver (without cylinder) it means a brutal crushing of his lungs: if at the surface he fills his chest with 6 liters of air, down below they become 0.285 liters. In scuba diving, the pressure does not compress the lungs, but the gas carried in the cylinder. The deeper the diver sinks, the denser this gas becomes and therefore the effort to inhale it increases. Another pressure problem, in any type of diving, is its action on the ears: the weight of water on the eardrums is increasing. These problems lead to believe that man is close to the depth limit in diving, although divers try to prove the opposite. “The more I advance, the more I believe that the limit does not exist”, says the Frenchman Loic Leferme, former world apnea record holder, with the mark of 171 meters.
Cable
The sled runs on a cable generally made of Teflon, a low-friction material that allows maximum speed on the descent. Record holder Patrick Musimu went to 209.6 meters and came back in 3 minutes and 28 seconds, that is, an average of 3.7 km/h
Balloon
When reaching the desired depth, the diver inflates the balloon over his head and heads for the surface at high speed. Some sleds have a pin, which automatically inflates the balloon when the diver lets go of the hands – others use a valve.
Equalization
The most difficult part of apnea diving is equalizing the pressure in the ears. For this, the Valsalva maneuver is used, which consists of covering the nostrils with the fingers or with a tampon and blowing through the nose, in order to push as much air into the ears as possible.
wetsuit
The deeper, the colder, after all, the sun’s rays do not reach the depths. For this reason, divers usually wear neoprene suits that are more than 1 centimeter thick. “At great depths, clothing is safety equipment,” says diver Karoline Meyer
Ballast
The sled is weighted to help you descend faster. In some apnea categories, there is a weight limit, but in Sem Limites, the diver determines the amount of ballast: if he is able to equalize the pressure in his ears, he puts on more weight and accelerates the descent