Forgetting to flip a single switch on your dive computer could land you in a recompression chamber—and it happens more often than you'd think. In this episode, veteran diver Ray Hollister breaks down exactly what nitrox mode does, how it recalculates your no-decompression limits, and why getting the setting wrong puts your nervous system at risk. Whether you're newly certified for enriched air or you've been diving EAN for years, this is essential knowledge for anyone breathing anything other than standard air underwater.

• Your dive computer's nitrox mode adjusts decompression calculations based on reduced nitrogen content in enriched air—feeding it the wrong gas mixture means dangerously inaccurate tissue loading math.

• Leaving your computer set to a nitrox mixture when breathing regular air is just as problematic ...