Human beings clearly cannot breathe underwater—which is why you should have a scuba tank with you during your dives. These tanks usually contain regular filtered air, trimix, or nitrox. Divers typically use nitrox air in their tanks if they want to spend more time underwater. But what exactly is nitrox and how does it help you while you’re diving?
What is Nitrox?
Nitrox is just what it sounds like: nitrogen mixed with oxygen. It’s also known as Enriched Air Nitrox (EANx) due to its increased oxygen percentage. This specific element sets it apart from other common diving gases.
Both recreational and technical divers use this breathing gas. In recreational diving, this breathing gas helps you absorb less nitrogen since it has more oxygen. Nitrox mixes usually contain more than 21% oxygen, but should not go above 40%.
Technical diving uses two nitrox-based mixtures: Nitrox I and Nitrox II. Both mixes combine pure oxygen and air. Nitrox I contains 32% of this combination, while Nitrox II has 36%. They also contain 68% and 64% of nitrogen, respectively.
But what are the advantages of using nitrox over regular air?
What are the Benefits of Nitrox Diving?
So why should you dive with nitrox? There are a few substantial advantages, which include the following:
Longer Bottom Times
Divers who use nitrox absorb less nitrogen, making them stay underwater for longer. They’re also less likely to get decompression sickness. It’s worth noting that older divers and those who’ve experienced decompression sickness or physical injuries can reduce no-decompression limits with the gas. It can even give you twice as much diving time at 50 to 100 feet in some cases.
But if you’re using a nitrox tank while diving, you shouldn’t go over your maximum depth or bottom time. You should also look at your depth gauge closely during dives. If you have a dive computer, setting a depth alarm is essential for nitrox diving. This alarm will warn you immediately if you’ve gone over your maximum depth.
Research hasn’t justified this advantage yet, but there are divers who report less fatigue with nitrox. But many divers believe that less nitrogen means fewer micro-bubbles in a diver’s bloodstream and less decompression stress. It can also make you less tired and drained after diving.
Longer Dive Times
Dives on air always have pretty short repetitive dive times, which is disappointing for divers who dive in exciting environments that beg to be explored. But absorbing less nitrogen on your first dive with nitrox gives you more repetitive dive times. You’ll also get around five more minutes at 70 feet when you use the gas. It may not seem like much, but those extra five minutes can be precious, depending on your dive.
Shorter Surface Intervals
Breathing nitrox also gives you shorter surface intervals. This is a great advantage, especially if you want to dive again. You’ll have less nitrogen to get rid of, which can make a remarkable difference in the time it takes to de-gas on the surface. But if you don’t want to put yourself or your dive buddy at risk, you should look at the correct times for surface intervals on dive tables before the actual dive.
What are the Disadvantages of Diving with Nitrox?
Despite its pros, nitrox diving also comes with some disadvantages and potential dangers. Understanding these risks is just as vital as getting the right training in using diving gear so you can enjoy a safe and fun dive underwater. Here are some cons you should consider before diving with nitrox.
Not Suitable for Deep Diving
Before you can use nitrox in scuba diving, you’ll need to go through special training and learn certain procedures in handling this gas. One misconception divers have about these key elements is that they will help in deep diving. But deeper depths will make nitrox poisonous.
Increased concentrations of oxygen can cause oxygen toxicity. Using nitrox in recreational diving can put you at risk for this condition. So before you dive with the gas, you should think about your oxygen limit. This factor covers your lungs’ exposure to oxygen and how long they should take it in while you’re underwater.
Acute oxygen toxicity comes with different symptoms, including distorted vision and convulsions. A nitrox diver with convulsions can drown and eventually die from it. By keeping a close eye on your maximum depth and total oxygen exposure, you won’t experience oxygen toxicity.
Diving Nitrox vs Air: Which Gas Should You Use?
We’ve covered the different pros and cons of nitrox diving, but there are two more factors you should consider when using this gas: cost and availability. Nitrox diving typically costs more than regular diving with filtered air for two reasons:
- Trained divers and dive shop personnel use special procedures and gear in producing the gas.
- Pure oxygen comes at a relatively expensive price.
You’ll also rarely see nitrox in most dive shops and destinations, even as it gets much more popular with recreational divers. And of course, scuba tanks still use compressed air for non-technical diving.
Getting Nitrox Certification
Nitrox diving can put you in danger while you’re underwater. This is why you should undergo special training for it. Proper training will help you understand how deep you can go with nitrox. And just like learning about diving gear and how you should use them, you’ll have a safer and greater diving experience when you know how to use the gas properly.
You can learn the following skills in an Enriched Air Nitrox course:
- Determining your oxygen exposure
- Analyzing your tank’s nitrox capacity
- Using special air tables and gear for producing enriched air
- Placing the right markings on your diving equipment
- Filling up your tank with the gas
- Programming your dive computer for nitrox diving
Many Open Water-certified divers eventually take an Enriched Air Diver Certification or nitrox certification course. PADI, TDI, and other scuba certification organizations offer EANx courses to aspiring nitrox divers.