Scuba diving with enriched air/nitrox gives the diver more no decompression time, especially on repetitive dives. It can also reduce fatigue. This is why the Enriched Air/Nitrox class is the most popular out of all the PADI courses.
If you are at least a PADI (Junior) Open Water Diver who 12 years or older then you can enroll in the Enriched Air Diver/Nitrox Specialty course. Check out the video below to learn more!