Since French chemist Antoine Laurent Lavoisier found and named oxygen in 1777, we’ve discovered so much about it. Oxygen is the third-most widespread component within the recognized universe and is clearly very important for all times. In leisure diving, we use more-concentrated oxygen mixes to assist circumnavigate a few of the legal guidelines of physics that govern leisure diving on conventional compressed air cylinders. A type of workarounds is the arrival of nitrox diving.
As you learn this, you’re respiration air, which is roughly 21 % oxygen. The rest, roughly 79 % (leaving apart roughly 1 % in hint gases), is nitrogen.
A nitrox, EANX or Enriched Air cylinder — relying in your location — has an elevated oxygen proportion inside. Often, we outline nitrox as having an oxygen content material of higher than 21 % and as much as a most of 40 %.
As a fuel, we have now used nitrox for a number of many years. Business-diving corporations and the Navy have used it because the 1950s. When it first appeared in a leisure setting, nevertheless, some divers seen nitrox with skepticism. However, its reputation has grown exponentially in tandem with using private dive computer systems. Now, on most dive boats and at most resorts, nitrox is the fuel of selection. Divers largely select nitrox as their default fuel for many dives within the 60-foot (18m) to 130-foot (40 m) vary, the place it’s best.
Why use it?
Divers primarily select nitrox to increase their backside time. You could recall studying throughout coaching that two elements primarily govern your backside time; first, your fuel consumption (or ‘SAC’ price). Second, notably as you progress past open-water diver (60 foot/18 m) suggestions, is your no-stop or no-decompression time. These two elements type the idea of your flip factors when planning and executing a dive.
Your no-decompression restrict is the utmost period of time you could spend at a given depth earlier than making obligatory decompression stops throughout ascent. The defining think about once you attain that point is the quantity of nitrogen you’ve absorbed whereas beneath strain.
For instance, utilizing a regular PADI/DSAT dive desk, a dive to 70 ft (21 m) provides a no-decompression restrict as 40 minutes with no earlier dives.
By changing a few of the nitrogen in your cylinder with oxygen and growing the general oxygen mix in your cylinder to 32 %, you possibly can prolong your no-decompression time restrict to 60 minutes.
Does that imply all my dives shall be longer?
No. Your personal fuel consumption — your ‘SAC price’ — will nonetheless issue into the dive, as will all the various different elements that govern period and depth. Your buddy, water temperature, logistical constraints, tides, dive boat/website guidelines — all play a task.
Are there another advantages?
Diving is statistically very protected and, subsequently, utilizing nitrox doesn’t imply that, statistically, you’re any safer. Nevertheless, diving an equivalent profile to an air diver you'll take up much less nitrogen and subsequently have much less DCS danger publicity. Certainly, many divers dive an air profile whereas utilizing nitrox for additional conservatism.
One other advantage of decreased nitrogen publicity on every dive is that floor intervals could also be shorter. Because of this in some circumstances, you could possibly get again within the water whereas your air counterparts should spend extra time on the boat.
Can I dive deeper on nitrox?
No. This can be a widespread false impression. The elevated oxygen content material in a nitrox cylinder does have sure issues although. Over-exposure to oxygen – both when it comes to exceeding depth limits or long-term over-exposure — can have critical implications. In these circumstances, you possibly can endure from oxygen toxicity. You have to acquire correct coaching to know the right way to handle these dangers and guarantee nitrox diving is extraordinarily protected.
Are there another hazards?
Figuring out precisely what's in your cylinder, personally analyzing your cylinder and planning your dive accordingly is vital to nitrox diving. Every particular person combine from 22 to 40 % has a maximum-operating depth (MOD). Consequently, the combination you employ will depend upon the dive you’re about to do, your earlier dives and the size of your floor interval. Utilizing the fallacious cylinder or an incorrect combine might have dire penalties. In some circumstances, a ship crew will put together totally different a special mixture of fuel in several cylinders relying on diver and dive-site necessities.
How would I determine a nitrox dive cylinder?
In lots of territories, nitrox cylinders have inexperienced and yellow markings and are marked with EANX/nitrox decals. Nevertheless, in different places, there are not any markings on the tank. As a rule, when boarding a dive boat or arriving at a dive middle, wait till they’ve given you a ready nitrox cylinder. Often all is revealed in the course of the boat or dive briefing.
Do I want particular gear to dive with nitrox?
Most diving gear is suitable with an oxygen content material of as much as 40 %. Past that, the combustibility of oxygen typically necessitates extra specialised gear.
Is nitrox coaching intensive?
No. Most bigger diver coaching businesses supply a leisure nitrox course you can full over just some hours. Often it features a mixture of e-learning, classroom educating and sensible software with nitrox cylinders. It’s very important that divers utilizing nitrox perceive easy methods to plan and execute their dives together with MOD, no-stop limits and easy methods to acknowledge and cope with oxygen toxicity. Understanding the advantages and the hazards of nitrox diving is vital, and no respected dive operation would provide you with nitrox cylinders with out proof of the right coaching and certification.
Who ought to use nitrox?
There are circumstances when you might not want nitrox, akin to shorter or shallower dives. Nevertheless, basically, it’s a boon to most divers. Whether or not you’re repetitive diving on a tropical dive vacation or need to safely spend a couple of additional minutes in your favourite cold-water wreck, nitrox pays dividends. With the right information and coaching, nitrox diving is a large profit and we advocate it to all.