Is the maximum depth of scuba diving 30 meters? Why can't scuba diving exceed 40 meters?

Dear friend, you want to go diving, but do you know some information about diving? For example, what is the maximum depth of scuba diving and why are there so many? There is also information about technical diving. Let's take a look with Bian Xiao.

Is the maximum depth of scuba diving 30 meters? Leisure scuba diving, standard depth 40 meters.

Popular scuba diving belongs to the category of leisure scuba diving. Ow deepest dive 18m, aow deepest dive 30m and deepest dive 40m.

The depth is mainly determined by the gas in the cylinder. The cylinder for leisure diving is filled with compressed air, and its main components are 2 1% oxygen and 79% nitrogen. Due to the pressure of seawater, the pressure under water increases by about one atmosphere per 10 meter. Even the simplest air, its two main components may be dangerous to divers. Nitrogen dissolved in the body under high pressure, in addition to the well-known diving disease caused by rising too fast and not being discharged, will lead to drunk nitrogen at too great a depth (generally more than 30 meters deep/after 4 atmospheres), but there are also great individual differences, which will lead to dizziness, slow response and loss of judgment like drunkenness. Oxygen under high pressure, if breathing for too long, will cause oxygen poisoning, which can be divided into central nervous system oxygen poisoning and lung oxygen poisoning. This is why the depth of leisure scuba diving will be set at 40 meters.

Technical diving, the deepest depth in the world is below 332 meters and 40 meters, usually requires the theory and technology of technical diving. Technical diving still needs to dive with a cylinder on your back, but the compressed gas in the cylinder is no longer ordinary air, and needs to be mixed with other gases, mainly helium (except helium, almost all gases will have anesthetic effect, including nitrogen, oxygen and carbon dioxide produced by breathing). As mentioned above, when the depth exceeds 40 meters, people's nerve center is prone to nitrogen poisoning, so helium will be added in deep technical diving to avoid this problem (and the decompression time required for ascending can also be reduced). The only drawback of helium is that it is very expensive. A helium gas cylinder costs hundreds of dollars when it is idle.

Therefore, technical diving needs to breathe mixed gas to go that deep. In addition, technical diving is also the most expensive diving, with high equipment price and high cost of mixed gas.

Why can't the maximum depth of scuba diving exceed 40 meters? Let's discuss it from the gas aspect first. Deep free diving (generally below 60 meters) may also lead to nitrogen poisoning. Although there is not much nitrogen in one breath, nitrogen poisoning can also occur at a large depth and pressure, coupled with factors such as cold, fear and tension on the seabed. However, nitrogen poisoning in free diving is not as serious as scuba diving. With more in-depth training and adaptation, the symptoms of nitrogen poisoning will weaken. Secondly, let's talk about oxygen. The depth and time of free diving depend more on oxygen. One breath of oxygen is limited. In the process of free diving, the body constantly consumes oxygen. When the body's oxygen content drops to nearly 0. 1bar, people's brain function will be shut down, leading to syncope (syncope in free diving). Finally, discuss the compression of lung. The lung is a big airbag of the human body. With the increase of depth, the lungs will be continuously compressed. When it drops to a depth of 30 meters, the lung will be compressed to 1/4 of the normal value. Physiological research shows that the lung is compressed to about 1/4, which is close to the limit of compression. With the diving reflex of mammals in the human body, blood will return to the chest. So when you dive freely to 30-40 meters, you will feel obvious abdominal and chest pressure. At this time, it is very important for free divers to relax physically and mentally, otherwise it is easy to have lung crush injury. Therefore, the depth of free diving is independent of the outside world, mainly determined by oxygen consumption and physical and mental relaxation.

Generally speaking, the diving depth of 40 meters is the safe depth for breathing ordinary compressed air. Technical diving is 332 meters, and it is necessary to supplement mixed gases such as helium by breathing. Free diving 130 depends on one breath, on the oxygen consumption of the body and the degree of physical and mental relaxation.