What might happen if a diver exceeds the Maximum Operating Depth (MOD) for a Nitrox blend?

Exceeding the Maximum Operating Depth (MOD) for a Nitrox blend significantly increases the risk of oxygen toxicity. Each Nitrox blend contains a higher concentration of oxygen than regular air, and oxygen toxicity occurs when the partial pressure of oxygen reaches levels that can have harmful effects on the central nervous system.

When a diver descends beyond the MOD, the increased pressure can elevate the partial pressure of oxygen to dangerous levels, leading to symptoms such as visual disturbances, muscle twitching, and in severe cases, convulsions. Understanding and adhering to MOD is crucial for safe diving practices to prevent these risks associated with elevated oxygen levels during deeper dives.

This principle is based on the biological effects of oxygen at pressures greater than normal atmospheric levels and serves as a critical guideline for Nitrox divers to ensure their safety while exploring underwater environments.