Deep Sea Diving: Trimix
One of the most important aspects of scuba diving that a diver has to study is how to set up the breathing tank. Divers do not use oxygen in their tanks, they use (or, increasingly, used to use) compressed air. However air is roughly 70 percent nitrogen and 30 percent oxygen and the nitrogen can cause nitrogen sickness under pressure, so more and more divers are turning to Nitrox.
Nitrox is not air, but it is still made up solely of nitrogen and oxygen, although not in the same percentages, which you can vary. The difficulty with increasing the amount of oxygen in the mix is that there is a greater likelihood of suffering from oxygen toxicity the deeper you go. Therefore, the trade off is that the more oxygen you use, the shallower you may swim.
It sounds like a rough decision, you can suffer from either nitrogen or oxygen toxicity, take your choice. However, there is a third option and it is called Trimix. Trimix is the ‘air’ that deep sea divers make use of. It is a mixture of three gases, as its name implies: nitrogen oxygen and helium.
Helium is used as a form of filler. It does not do us any harm and it does not do us any good either, but it permits divers to take a lung full and it reduces the volume of nitrogen and the volume of oxygen thus reducing the chance of illness.
The only problem with helium is that it conducts heat five times faster oxygen and nitrogen. This leads some deep sea divers to suffer from a condition known as hyperbaric arthralgia. Hyperbaric arthralgia is a kind of joint pain that some divers experience as they go deeper than 100 feet in salt water.
Deep sea divers have to learn about the various Trimixes as part of their course, because one day they will be accountable for selecting the mix they use. The choice is not only compressed air, nitrox and Trimix, because there are different ratios of the gases in Trimix to take into the equation too.
For example, a 10/70 Trimix will be composed of 10 percent oxygen, 70 percent helium (and 20 percent nitrogen). This kind of mix is appropriate for diving to a depth of 330 feet in salt water or 100 msw (metres in salt water). Fresh water is a little lighter than salt water. This does not matter at lower depths, but it does after a hundred feet.
Breathing and gases are merely one aspect of diving that you will have to master if you would like to go diving. Another aspect of diving that is associated with diving is the speed of ascent. Divers used to get taught not to rise faster than their smallest bubbles, which is around 60 feet per minute. However, many instructors now think that this is still quite fast and recommend 30 feet per minute with a three minute wait at 15 feet.
Owen Jones, the author of this article, writes on a lot of topics, but is currently occupied with Body Glove cases products. If you would like to know more about Body Glove Wetsuit Sale, please go over to our website for some impressive bargains.