Nitrox diving is gaining popularity as it allows for longer dives and reduces the risk of decompression sickness. Nitrox is a mixture of nitrogen and oxygen, with more oxygen than air on the earth’s surface. Nitrox diving modifies the air mix to maximize bottom time and minimize surface intervals. There are two types of nitrox: hypoxic and hyperoxic. Recreational divers should only use hyperoxic nitrox. Nitrox diving reduces the risk of nitrogen narcosis but does not eliminate it. Nitrox tanks and valves must be handled and cleaned properly to avoid explosions. Understanding and adhering to principles is imperative for safety.
Nitrox diving is a method of scuba diving that is steadily gaining popularity among divers looking to dive for longer periods of time. It also reduces the chances of having common complications that divers can suffer, such as decompression sickness, also known as bends.
The word “nitrox” is a portmanteau of the words nitrogen and oxygen and can actually be used to mean a mixture of the two gases in any ratio. The air on the earth’s surface, which is approximately 78% nitrogen and 21% oxygen (with 1% trace gases), is a form of nitrox. The nitrox used for diving, however, has more oxygen than the kind on the earth’s surface.
The key difference between normal scuba diving and nitrox diving is in the type of air used in the diver’s tank. Regular diving has a very specific ratio of nitrogen to oxygen; try to mimic the air found on the earth’s surface as much as possible. Nitrox diving, on the other hand, modifies this mix to maximize bottom time (i.e., the diver’s time spent underwater) and minimize surface intervals (i.e., time the diver must remain on the surface). before diving again).
While nitrox can come in a variety of ratios, they are usually classified into two types: hypoxic which contains a lower percentage of oxygen than normal air (i.e. less than 21%) and hyperoxic nitrox which contains more than 21% oxygen . Recreational and sport divers should only use hyperoxic nitrox mixes. These types of nitrox may also be called SafeAir or enriched air nitrox (EAN or EANx). There are two general types of underwater nitrox: Nitrox I, also called Nitrox 32, which is 32% oxygen and 68% nitrogen; and Nitrox II, also called Nitrox 36, which comprises 36% oxygen and 64% nitrogen.
The principle behind diving with nitrox is relatively simple. The longer and deeper a diver is underwater, the more nitrogen enters his system. Too much nitrogen in his system can lead to a number of debilitating diseases, some of which can ultimately lead to death. To combat this, a diver must ascend slowly, make decompression stops, and adhere to the recommended surface interval before the next dive. For the recreational or sport nitrox diver, however, the plan is a little different. Since his “enriched” air has more oxygen and less nitrogen, his body will absorb less nitrogen than the diver using a regular tank. As a result, the nitrox diver may spend more time underwater, less time on decompression stops and surface intervals, and in some cases may not need to at all. Some divers also report the benefit of being less tired after a nitrox dive compared to a normal dive.
While nitrox certainly has its benefits, there are some additional precautions nitrox divers should observe. Because nitrox contains more oxygen, and oxygen is actually toxic at certain depths, nitrox divers are at a higher risk of oxygen toxicity or oxygen poisoning. As a result, nitrox divers should be sure to observe the depth limits associated with particular nitrox mixes.
Increasing the amount of oxygen in the nitrox does not only affect the associated depth limits. Because nitrox contains a higher proportion of oxygen, it is actually flammable. Nitrox tanks and valves must therefore be handled and cleaned properly so as not to cause unwanted explosions.
While nitrox diving is certainly gaining many followers, there is still a lot of confusion surrounding it, usually taking one of two forms. While some may believe that diving with nitrox will allow them to dive deeper, that is not the case. In fact, the higher the percentage of oxygen in the nitrox mix, the shallower the maximum working depth becomes. Another common misconception among some untrained divers is that nitrox diving does not carry the normal diving risks of suffering from illnesses such as stoops. While it is true that the risk of nitrogen narcosis can be reduced, it is not eliminated.
In such a highly technical sport as nitrox diving, it is imperative that one understands and adheres to the principles involved. After all, it could help save your life.