What does Equivalent Air Depth (EAD) refer to in diving?

Equivalent Air Depth (EAD) is a concept used in Nitrox diving that allows divers to understand the nitrogen loading they would experience when using a Nitrox mixture, compared to diving with regular air. The correct answer states that breathing a particular Nitrox mixture at a depth exposes your body to the same overall nitrogen level experienced by breathing air at a shallower depth.

This concept is essential because different Nitrox mixtures have varying concentrations of oxygen and nitrogen, which impacts how much nitrogen the body absorbs at depth. By calculating EAD, divers can determine a depth at which their exposure to nitrogen would be equivalent if they were diving with regular air. This process helps divers to optimize their dive plans by minimizing the risk of decompression sickness.

The other options address different aspects of diving but do not accurately describe the function of EAD. Breathing a Nitrox mixture actually provides benefits in terms of reduced nitrogen absorption; hence, it is incorrect to say that it exposes the body to higher nitrogen levels or that there’s no difference compared to air at the same depth.