How does a diver calculate the total time spent underwater during multiple dives?

To accurately calculate the total time spent underwater during multiple dives, a diver must sum the bottom times of each dive while also accounting for any surface intervals between those dives. This approach provides a comprehensive view of the diver's exposure to the underwater environment.

Bottom time refers to the duration spent at depth, and surface intervals are critical because they allow for off-gassing of nitrogen that may have accumulated in the body due to the pressures experienced during diving. By accurately tracking both the total bottom times and the surface intervals, divers can effectively manage their nitrogen absorption and ensure they stay within safe limits for diving.

Relying solely on a dive computer may lead to an incomplete understanding of total dive time, as these devices often focus primarily on the current dive and its specific parameters without considering cumulative effects from previous dives. Averaging the bottom times does not accurately represent the total time spent underwater and can lead to miscalculations regarding residual nitrogen levels. Estimating based on air supply also introduces variability and imprecision, as air consumption rates can vary significantly among divers based on factors like exertion and individual physiology.

Therefore, methodically summing actual bottom times along with proper consideration for surface intervals provides the most accurate account of total underwater time, thus ensuring diver safety and adherence