Divers all over the world know that the limit for recreational diving is 40 meters. This would be achieved using ordinary nitrox which is basically the same air that we breathe only a slightly higher percentage of oxygen. This limit is presented by the Professional Association of Diving Instructors. This is for the protection of divers all over the world.
But, there are a few who brave the dangers of recreational diving to claim the record for experiencing the deepest dive made by a human. If ever a human goes down as deep as 300 meters, he will have to take even more time to resurface and would have to be placed in a hyperbaric chamber afterwards.
Deepest Dive By Human Without Oxygen
The record for having the deepest dive by human without any oxygen apparatus was made by Herbert Nitsch. He set a new record of 214 meters or 702 feet deep. This record confirmed that Herbert is the deepest man diver ever on this planet. The dive was 29 meters deeper than the previous record which was held also by himself. The dive took place in Spetses, Greece. The entire experience was monitored by 3 SUUNTO Dive Computers which gave the rough estimate of the dive.
The maximum depth that a person can dive safely is dependent on how well the person is trained to accommodate the oxygen requirement of the body. If a person has trained for years through constant deep diving, the body begins to adapt to the tremendous pressure under water. If the person is not fully trained, the body will slowly become toxic. The air we breathe on the surface is at 0.2 bar. By the time the body reaches 10 meters below, it hits 0.3 bar. Oxygen begins to be toxic for the body when it reaches 1.6 bar.
Deep Diving Gas Mixtures
The air we breathe is a mixture of oxygen, nitrogen, and several other gases. We breathe about 19 percent of oxygen, 80 percent of which is nitrogen, and 1 percent are other gases. The same composition of the air we breathe can help keep us alive under normal circumstances but the time we go deeper underwater, the same gas mixtures can also kill us. In order to prevent this gas mixture from destroying the body when going deep under water, divers usually use tri-mix gas. This is why deep sea diving is limited to 40 meters if divers do not use any breathing apparatus. If a diver has to dive under such circumstances, tremendous amounts of preparation and training is require before doing the dive.
The purpose behind this is to allow the body to decompress and allow the bubbles of nitrogen to exit the bloodstream thus preventing decompression injuries. Oxygen toxicity can result to seizures and can result to death if not treated properly. It would be very unwise to venture beyond the limits of recreational diving given by international organizations especially without proper technical training given by professional divers.