The TDI Advanced Nitrox Course qualifies divers to use enriched air nitrox from EAN 21 through EAN 100 to a depth of 40 metres/130 feet during dives hat do not require staged decompression. Advanced Nitrox is also a great course for those wanting to extend their bottom times in shallower depths such as scientific diver, and a must for SCR or CCR divers. The course cover topics like: