In [Scuba diving](Scuba%20diving.md), when we're going deeper, the pressure increase, and so the amount of nitrogen that goes into our tissues and our blood. When we're exposed to a long period of too much nitrogen, we start to be narked. What it basically does, it's that we start to have a drunkenness feeling. Some people start being narked faster than other, but people agree that the mean depth that start provoking narcosis is around 3,5ppn2 (partial pressure of n2), so ~-32m for around 10 minutes of exposure. The deeper you go, the harder is narcosis and this can result in the loss of cognitive senses and worst, loss of biological function. To avoid nitrogen narcosis, we need to breath nitrogen underweighted mixing gas, such as the [Nitrox](Nitrox.md) or a [Trimix](Trimix.md). **Links :** * [Nitrogen narcosis - Wikipedia](https://en.wikipedia.org/wiki/Nitrogen_narcosis)