Diving with Nitrox

Scuba tanks with green and yellow nitrox labels

Scuba Diving with Nitrox

There are many benefits of using nitrox while scuba diving as opposed to diving with air. Of course, there are risks and considerations for diving with nitrox. Some experienced divers feel the benefits of diving with nitrox far outweigh the risks, and they choose to use nitrox at every opportunity.

1. Shorter Times at the Surface

A diver who uses nitrox absorbs less nitrogen on a given dive than a diver who uses air. This means that the diver using nitrox has less nitrogen to ‘off-gas’ during the surface interval, which means that he does not have to wait as long at the surface as the diver who uses air.

2. Longer Bottom Times

Because the nitrox diver is breathing a lower amount of nitrogen during the dive, his body is absorbing it slower than it normally would. For example, a scuba diver breathing air would have a no-decompression limit of about 56 minutes at around 18 meters. However, if the same scuba diver were diving with 36% nitrox mix, even at the same depth, his or her limit would now be 130 minutes. Typically, enriched air blends are best used at depths that range from 15 to 30 metres. If you're diving in shallower water, the no-decompression limit is so long already that you won't need to extend it.

3. Longer Repetitive Dive Times

Nitrox becomes especially useful for divers who dive regularly and practice repetitive dives. A diver using nitrox will have a longer permitted bottom time whilst diving repetitive dives than a diver who is using air. This is because the diver using nitrox has absorbed less nitrogen. For example, after a dive to 21 metres for 30 minutes, a diver using Nitrox 32% can stay at 21 metres for a maximum of 24 minutes if he immediately re-enters the water. However, a diver performing the same series of dives using air can only stay at 21 metres for 19 minutes on his second dive.

4. Post-Dive Exhaustion

There are many divers who claim to feel less tired after a diving with nitrox than after a similar dive using air. By reducing a diver's nitrogen absorption, nitrox may also reduce a diver's post-dive exhaustion. This is not a proven fact, but enough divers claim to feel this effect that it is definitely a consideration.

5. Shorter Decompression

Technical divers use nitrox to reduce decompression requirements. If nitrox is used throughout the dive, the diver may require shorter or fewer decompression stops. If nitrox is used as a decompression gas (the diver only breathes nitrox during the decompression stops), the decompression stops will be shorter.

You'll need extra training and education about diving with Nitrox before you should consider using it. As mentioned before diving with Nitrox does have some additional risks. The more severe is the risk of oxygen toxicity. Under pressure oxygen can become a toxic and deadly gas. Oxygen toxicity will not be a problem if you stick to the maximum depth you are trained to dive to. As always with any kind of diving, stay well within your limits at all times.