Not an Enriched Air Diver yet??
Recreational Nitrox (21 – 40% oxygen) contains a lower percentage of nitrogen than air. The reduced percentage of nitrogen in recreational Nitrox allows divers to extend their no-decompression limits (or dive time) by reducing nitrogen absorption – the less nitrogen there is in a diver’s breathing gas, the slower his nitrogen absorption will be at a given depth.
A diver using Nitrox absorbs less nitrogen for a given depth and dive time than a diver using air. This means that the Nitrox diver has less nitrogen to off-gas during a surface interval, which can shorten the required surface interval drastically.
Nitrox becomes especially useful for divers who engage in more than one dive per a day. A diver using Nitrox will have a longer allowable bottom time on a repetitive dive than a diver using air because the diver using Nitrox has absorbed less nitrogen.
Many divers claim to feel less exhausted after a dive on Nitrox than after a comparable dive on air. By reducing a diver’s nitrogen absorption, Nitrox may also reduce a diver’s post-dive exhaustion.
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.