In this blog post we’ll be talking about diving with Enriched Air Nitrox, what Nitrox is, how you can benefit from this specialty course, some important facts you’ll learn in the theory part and the process before diving with Nitrox.

The exact oxygen percentage will mostly be adapted to your dive site and the maximum depth you want to dive. Depending on where you are diving, most of the diving centers can mix Enriched Air Nitrox with a small surcharge or even for free.

Pro Tip: However, we would advise that the first time you go diving with Nitrox, you should talk to your diving center or your guide that they can show you everything shortly in “real” life.

While the lower nitrogen percentage in a Nitrox mixture has a positive effect on the no-decompression time, the increased oxygen percentage also has a disadvantage:

Breathing oxygen under increased pressure is toxic for your body and has an impact on your central nervous system with symptoms like cramps, visual disturbance, nausea, muscle spasms, dizziness and ringing in the ears.

However, the point at which oxygen becomes toxic can be calculated!

ppO2 = depth in bar x fO2

You want to visit a wreck in maximum 33 meters depth, therefore you have 4.3 bars down there.

Now you need to multiply this value with the oxygen percentage you’re diving with, which is for example 32% -> 4.3 x 0.32 = 1.38, which is perfect because it’s within the recommended limit value of 1.4.

If you would have a EAN36 mixture, it would be 4.3 x 0.36 = 1.55, which would be miserable for your body!

Depth / EANx | 21% | 32% | 36% |

15m | 0,53 | 0,80 | 0,90 |

33m | 0,90 | 1,38 | 1,55 |

37m | 0,99 | 1,50 | 1,69 |

Therefore this is the formula:

For example, you’ve analysed EAN32:

MOD = 33,7

This means, your maximum operating depth with EAN32 is 33,7 meters. Always keep that in mind while diving.

PPO2 | Singel Dive | Daily Maximum |
---|---|---|

1,6 | 45 Min | 150 Min |

1,4 | 150 Min | 180 Min |

1,2 | 210 Min | 240 Min |

Diving with a ppO2 of 1.6 bar one single dive can only take 45 minutes, whereas with a ppO2 of 1.4 bar one single dive can take up to 150 minutes. The daily maximum in these two examples would be 150 or 180 minutes for a 24-hour period.

First of all, the only way to visually identify a tank filled with EAN is a marker on the tank. This can be a green/yellow colored “ENRICHED AIR NITROX” label around the tank or just a tank tag like in the picture above.

But as we learned in the theory facts, it’s very important to really know the exact percentage of the oxygen in your tank. Therefore the diving center will give you an analyzer and every diver needs to follow these steps:

__For example:__ We once had a dive where our MOD within the 1.4 partial pressure was exact the depth of the wreck entrance. Therefore we adjusted the partial pressure on our computer to 1.6 for two reasons: We didn't want it to beep all the time and we wanted to eliminate the risk of it being too strict with us and not allowing itself to be served for 24 hours. Caution: Only do this if you know what you are doing and you really know the maximum depth of the dive.

If you have any further questions, don’t hesitate to contact us.

Tami and Chris