What is Trimix?

If you think that scuba diving is all about attaching an oxygen tank to your back and breathing through it with the use of a regulator, then you are wrong. There's a lot more to scuba diving than that. In fact, pure oxygen is never used in scuba diving, especially on deep sea diving.

In recreational diving, air is commonly used and not pure oxygen as most people assume. Air is basically composed of 70 percent nitrogen and 30 percent oxygen. However, nitrox mixes are now being used a lot more in recreational diving as it decreases the chances of nitrogen sickness.

Although nitrox is still composed of nitrogen and oxygen, the oxygen concentration is a lot higher than air. This will reduce the risk of nitrogen sickness or bends, but it trades off depth. The more oxygen there is in your scuba diving tank, the shallower you are allowed to dive.

So, just why is pure oxygen not used in deep sea diving? This is because of oxygen toxicity. As you go deeper underwater, the pressure increases and oxygen toxicity becomes a factor. So, by reducing oxygen in the air you breathe, you will be able to go deeper. However, by doing so, you will also increase the amount of nitrogen in the air you are breathing which can result in nitrogen narcosis when you go deeper as well as nitrogen sickness or the bends.

You may wonder how deep sea divers go deep underwater.

The answer to this question is trimix. Trimix is a special air mix designed for deep sea diving. Trimix is composed of oxygen, nitrogen and helium hence the term trimix.

Helium is used because it reduces the proportions of nitrogen and oxygen. This means that because the oxygen is reduced, it will enable the diver to dive deeper. And, because nitrogen is reduced, the diver will not experience nitrogen sickness or nitrogen narcosis.

The great thing about helium is that it can be breathable under pressure and it has very little narcotic effect. Because of helium's low density, it reduces breathing resistance at depth or at pressure.

Also, helium does not enter slow tissues as readily as nitrogen, which causes the bends.

The only disadvantage of helium is that it conducts heat 5 times faster. Also, during descent, deep sea divers suffer from a condition called hyperbaric arthralgia.

If you become a deep sea diver, you will learn about the different variations of trimix. Some will be named trimix 10/70 and etc. If you come across trimix 10/70, it will mean that the gas inside the scuba diving tank will be composed of 10 percent oxygen, 70 percent helium and 20 percent nitrogen. This kind of mix is suitable for dives up to a hundred meters or 330 feet.

These are the things that you have to remember about trimix. As you can see, deep sea diving is not as simple as it may seem. There are so many aspects in deep sea diving that you have to be aware of and one of them is the gas used for breathing.

So, before you don your scuba diving gears and you plan on going very deep, keep in mind that deep sea diving is a specialty course that one needs to take before they undertake dives like this. Deep sea diving is different from recreational diving. It takes years of training and a lot of discipline.