What indicates the maximum depth attained prior to initiating oxygen procedures?

The maximum depth attained prior to initiating oxygen procedures is indicated by the highest depth reached during the dive. This measurement is crucial because it provides the necessary information to assess the potential risks associated with decompression sickness and hypoxia. Understanding the maximum depth allows for correct calculations to be made regarding decompression schedules and any required safety stops before ascending.

Recognizing the highest depth also helps in tailoring the oxygen procedures to the diver's specific experiences and conditions during the dive. This focus on the deepest point reached ensures that medical protocols are adhered to for optimal safety and health following the dive. Each of the other choices lacks a direct relationship to the actual conditions encountered during the dive that would necessitate the initiation of oxygen procedures. For instance, average depth may not convey the risks associated with deeper depths, while symptoms experienced are subjective and can vary significantly among divers. Planned depth, although relevant, does not reflect the actual conditions that must be addressed in post-dive protocols.