PADI or ProNRC Enriched Air Diver (Nitrox) Specialty Course (1-2 days)
The primary reason to dive using Enriched Air is to extend your No Decompression Limit (NDL), sometimes quite dramatically, giving you longer dives than would be possible on standard compressed air. As an example, a dive to 25 m/80 ft on air has an NDL of just 30 minutes. The same dive made using EAN36 has an NDL of 55 minutes, which is a whopping 25 minutes (83%) extra dive time!. Some divers also say that they feel less tired after making a series of dives when they use Nitrox. This specialty does not require diving but just the theory.
Alternative course:
ProNRC (Professional Nitrox & Rebreather College) course is: IDR 2,250,000/person