When conducting a repetitive dive to less than 40 feet, which depth should be used on the dive tables?

In the context of repetitive diving, the depth that should be recorded on the dive tables is the maximum depth reached during any of the dives in a specific series. If the maximum depth of the dive is less than or equal to 40 feet, you would use 40 feet for the calculations on your dive tables. This is important because the calculations for no-decompression limits, surface intervals, and residual nitrogen in your body are all based on the maximum depth of the dive.

Using 40 feet allows you to correctly assess the necessary safety measures and limits for subsequent dives. If the previous dives were at shallower depths, the data would still be based on the deeper limit to ensure a safe ascent and avoid the risks associated with decompression sickness. The dive tables are specifically designed to account for the decompression status resulting from the deepest depth reached, thus providing a comprehensive safety guideline for divers engaged in repetitive diving.