For many enthusiasts, there is one drawback with traditional SCUBA diving: Divers can only stay under the water for a limited amount of time, even with oxygen tanks. An alternative method of diving, though, known as nitrox diving, can allow divers more underwater time. While nitrox diving is attracting a growing number of supporters, it’s important for divers to learn the basic safety rules before attempting it.
Nitrox diving takes its name from the combination of the words “oxygen” and “nitrogen.” This is appropriate, as nitrox is a special combination of nitrogen and oxygen that allows divers to spend more time under the water and less time on the surface. As a matter of fact, the air you are breathing right now is about 21% oxygen, 79% nitrogen.
Of course, divers usually rely on a combination of nitrogen and oxygen when diving. But in nitrox diving, the two gases are mixed in a very specific way. In regular SCUBA diving, the goal is to mix the gases in a way that mimics the air found on the surface of the earth. In nitrox diving, the mixture is changed. The new nitrox air is supposed to allow divers to maximize the amount of time they actually spend under the water.
It is also designed to reduce the amount of time divers have to spend on the surface before diving back under the water. Normally divers use the decompression tables and a dive computer to figure out how long to stay down- there are also specially designed nitrox dive computers available as well.
Nitrox mixes,come in a variety of ratios, are typically considered either hypoxic or hyperoxic. Hypoxic nitrox mixes contain less than 21 percent oxygen, while hyperoxic mixes contain more than 21 percent. Divers who dive for recreational or sporting purposes, are only allowed to use hyperoxic nitrox mixes. Because divers using nitrox mixes will have a greater amount of oxygen and a lesser level of nitrogen in the air they are breathing in, they can spend more time underwater. They also have to make fewer decompression stops and spend less time on the surface waiting for the chance to dive again.
There are some safety issues that nitrox divers need to be aware of before diving. For instance, those who dive with the wrong nitrox mix may suffer serious complications as they swim deeper under the surface. Certain combinations of oxygen and nitrogen do not work well at some depths. There is also the misconception among some divers that nitrox diving allows them to dive deeper under the surface. This, though, is not true. The more oxygen there is in an air mix, the shallower a diver’s dives will have to become. Nitrox allows divers to stay underwater longer. It doesn’t allow them to dive deeper into it. A good air integrated dive computer can assist with computation of safe ascents when nitrox diving.