What is the cumulative exposure limit for Nitrox at its Maximum Operating Depth (MOD) in a 24-hour period?

In the context of Nitrox diving, the Maximum Operating Depth (MOD) is the deepest depth at which a specific nitrox blend can be used without exceeding a predetermined partial pressure of oxygen. The cumulative exposure limit refers to the amount of time one can safely spend at the MOD in a 24-hour period while minimizing the risk of oxygen toxicity.

The correct response indicates that the cumulative exposure time at the MOD is set at two and a half hours. This limit is derived from guidelines established by various diving organizations, which take into account the increased risk of oxygen toxicity the deeper and longer one remains at depth.

Understanding this limit is crucial for divers to safely plan their dives and to avoid exceeding the recommended exposure duration, thus ensuring their safety and well-being while using Nitrox mixtures. Knowledge of the cumulative exposure limits allows divers to effectively manage their dive profiles, plan surface intervals, and determine their readiness for subsequent dives.