Are you looking to expand your dive time? Maybe you’re a scientific diver or photographer looking to stay in the water a little longer? The TDI Advanced Nitrox Course qualifies divers to use enriched air nitrox from EAN 21 through EAN 100 percent within your current certification level to a maximum depth of 40 meters/130 feet during dives that do not require staged decompression. Often taught in conjunction with the TDI Decompression Procedures course, this can be considered the foundation of your technical diving career.