5 Types of Mixed Gas Diving or Gas Blending

If you are a follower of this blog, you already know that there are different mixed gas diving possibilities. In this article we are going to review them, to delve into their properties and we will also see new mixtures we had not yet told you about.

Recreational Mixed Gas Diving

1. Compressed air. This is the most common mixture, the mixed gas diving percentage is 21% oxygen, 78% nitrogen, and 1% other trace gases. The use of this gas blending does not require training beyond that obtained in the Open Water course. This is not the case with all other mixed gas diving.
   This gas blending is only usable up to 40 meters / 130 feet, which are the limits of recreational diving. If you want to delve into this topic, we recommend the article Open Water Depth Limits: Everything You Should Know. The main problem is the nitrogen contained in this mixed gas diving. Beyond 40 meters / 130 feet depth, there is a danger of nitrogen narcosis. Also, as we know, nitrogen dissolves in the body and you need a slower ascent rate and decompression stops to safely remove it. This is the reason why other mixes are used.

2. Nitrox or enriched air EAN. This mixed gas diving allows you to increase underwater time, but it does not allow you to dive deeper. Why? As we already told you in the article. 5 Reasons to become a PADI Enriched Air Diver there are different Nitrox gas blendings.

• EAN32 or Nitrox I: 32% oxygen and 68% nitrogen. This is the mixed gas diving that you can find in Dressel Divers and enjoy for free.
• EAN36 or Nitrox II: 36% oxygen and 64% nitrogen.
• EAN40: 40% oxygen and 60% nitrogen.

As you can see, the percentage of oxygen is higher in any Nitrox gas blending than in the compressed air. This poses a risk due to the toxicity of oxygen at high pressures. The more oxygen the mix has, the less depth you can go. This is why Nitrox divers must be trained as they need to learn how to calculate what their exposure to oxygen is going to be, based on the pressure and duration of the dive.

Technical Mixed Gas Diving

3. Trimix: We already told you about this mixed gas diving in the article: ” Trimix Diving or How to Go Deeper ” In Trimix, oxygen, nitrogen and helium are mixed in different percentages depending on the diver’s needs. By substituting part of the oxygen for helium, we reduce the risk of oxygen toxicity or nitrogen narcosis. Therefore, this mixture of diving gases allows us to descend deeper. Of course, anyone who intends to dive with Trimix needs additional training.

The basic problem with Trimix is ​​that Helium is very expensive and its price rises more and more.