Why should Nitrox divers be cautious at shallow depths?

Nitrox divers should be cautious at shallow depths primarily because shallow depths can still lead to nitrogen loading. When divers use Nitrox, the mixture typically has a lower percentage of nitrogen compared to regular air, reducing the amount of nitrogen absorbed by the body during a dive. However, even at shallow depths, nitrogen can still be absorbed, and multiple dives, prolonged bottom times, or repetitive dives can contribute to nitrogen buildup.

Understanding this is crucial, as nitrogen loading can lead to decompression sickness if a diver ascends too quickly or fails to adhere to appropriate dive tables or computer algorithms that account for their nitrogen exposure. Therefore, while it's true that deeper depths present a higher risk of nitrogen narcosis or oxygen toxicity with higher partial pressures of gases, shallow depths require divers to be mindful of their nitrogen exposure and plan their dives accordingly, ensuring safe ascent rates and adhering to no-decompression limits.