PADI Nitrox Certification

The PADI (Professional Association of Diving Instructors) enriched air or "nitrox" certification is a specialty scuba diving certification offered by the association. After being certified as an open water diver, you can learn how to breathe nitrox--an oxygen-rich mixture that allows you to stay under water for longer periods with less risk of experiencing decompression illness, or "the bends."

  1. Significance

    • The significance of enriched air, or nitrox, certification is that it allows you to dive with other divers also certified to breathe this mixture. Getting certified allows you to dive in places where divers that are not nitrox certified cannot dive. It also reduces the risks associated with absorbing nitrogen when breathing normal compressed air.

    Benefits

    • A PADI nitrox certification gives you more of what you got into diving for--time underwater. On repetitive dives and single-level dives we sometimes run out of "no-stop time." No-stop time is a dive made with no decompression limits because you don't have any required decompression stops. Nitrox extends the amount of time you can stay underwater without having to stop and decompress the gases that accumulate in your body.

    Types

    • According to the PADI "Enriched Air Diving Manual," nitrox has more oxygen and less nitrogen than normal air. Normal air consists of 21 percent oxygen and 79 percent nitrogen. The two most common nitrox mixes are 36 percent oxygen to 64 percent nitrogen and 40 percent oxygen to 60 percent nitrogen. By replacing some of the nitrogen with oxygen, you absorb less nitrogen than when breathing normal air.

    Time Frame

    • PADI nitrox certification is typically earned over a weekend, but it can be done in as little as one day. There are two parts to getting certified: classroom learning and hands-on diving. Classroom learning consists of purchasing the PADI "Enriched Air Diver Manual," studying it and then passing a practical exam. The hands-on diving consists of two dives in which you learn to analyze the oxygen content in your tank followed by two dives while breathing nitrox.

    Warning

    • Once certified, there are dangers associated with diving with nitrox. While breathing nitrox reduces the potential of getting "the bends," it increases the risk of oxygen toxicity. The main type of oxygen toxicity that concerns recreational divers is central nervous system (CNS) toxicity, according PADI. CNS toxicity can make a diver convulse, and underwater convulsions can make a diver lose her regulator and drown.

    Prevention/Solution

    • To avoid oxygen toxicity, maintain good buoyancy control, navigate properly and pay attention to any warning signs and symptoms of a CNS convulsion. According to PADI, symptoms include visual disturbances, ear ringing, nausea, facial twitching or muscle spasms and dizziness. Oxygen exposure risks can be managed if you remember to dive conservatively and follow the rules.