Exploring the ocean is an amazing experience that you never get tired of because there’s always something new and exciting waiting for you. Going beneath the waves to enter the deep blue waters somehow awakens your childhood-like curiosity as you encounter different forms of life. No wonder, many divers wish they could spend more time under the ocean. If you’re one of those divers yearning for longer dives to maximize underwater adventure, then you might want to consider diving with Enriched Air Nitrox (EANx).
This is not something new because divers have been diving with Enriched Air Nitrox for the past decades but not everyone is familiar with it. Chances are, you might have spotted these cylinders with bright-yellow and green bands on the boat during one of your group diving trips. Let’s delve into EANx so you can understand it better and determine if it’s something for you.
Air is composed naturally of 21% oxygen and 79% nitrogen and the term Nitrox is a fusion of these two elements. Diving with EANx means using a mixture of these gasses with a bigger percentage of oxygen than in normal atmospheric air. Divers may use 21-40% oxygen and 60-79% nitrogen but the most common mixtures are Nitrox 32 (32% oxygen) and Nitrox 36 (36% oxygen). There are more possible mixes but blends involving more than 40% oxygen are quite rare in recreational diving.
Advantages of EANx
The lower percentage of nitrogen in EANx lets divers extend their no-decompression limits or lengthen the time spent underwater by significantly lessening the amount of nitrogen absorbed by the body. For multiple dives, the percentage of nitrogen from one dive to another is lower compared with atmospheric air which allows you to decrease surface intervals. Thus, you absorb lower nitrogen for a given depth and dive compared to a diver using air.
By reducing the amount of nitrogen in your mixture of gasses, it lowers the risk of decompression illness which may happen during long and repetitive dives. Also referred to as generalized barotrauma or “the bends”, this illness is caused by the brisk decrease in the pressure around you. When you descend underwater with compressed air, you absorb extra oxygen and nitrogen; the former is used up by your body but the latter is dissolved into your blood. After going on a deep dive, the water pressure around you goes down as you make your way back to the surface. If you make your ascent too quickly, the nitrogen does not have a chance to clear from your blood but instead, it creates nitrogen bubbles that can potentially damage blood vessels and block normal blood flow. Descending underwater with EANx can protect you from this kind of dangers associated with decompression sickness.
Using enriched mixture of gasses also reduce post-dive exhaustion which is probably due to the increased oxygen supply to the muscles. If you normally feel tired after diving with air, you might be surprised that you still have energy left in you after a similar dive using ENAx.
Disadvantages of EANx
Now that you already know the benefits of using enriched mixture of gasses, it’s equally important that you’re also fully aware of its downside. While oxygen is vital in life, very high concentrations can lead to oxygen toxicity, a medical condition attributed to the exposure to oxygen at high pressure. Scuba divers who go very deep, in excess of 220 feet face the risk of acute oxygen toxicity which may cause dizziness, nausea and vomiting, visual and hearing distortions, convulsions, pulmonary barotrauma, and in extreme cases even death. To avoid this, you must be mindful of your oxygen limit when going in the water with EANx by considering factors such as the amount of exposure and length of exposure. In line with this, your dive instructor can help you compute your maximum operating depth (MOD) to avoid going beyond the safe depth limitations of your mix.
Creating enriched air requires the use of certain equipment, special procedures, and analyzers. Pure oxygen used for blending gasses is also quite pricey which makes ENAx more expensive than air.
Another downside is that it’s not always available since not all dive shops offer it and not all destinations carry it.
Enriched Air Nitrox diving requires specialized training so do not attempt it without taking a proper course. If you want to pursue diving with EANx, you can get a Nitrox Certification which involves undergoing a specialty course to use special mixture of gasses. Learn everything you need to know about it from dive planning techniques down to enriched air blending.