What would your minimum surface interval be if you wanted to make two dives to 60 feet for 30 minutes each?

To determine the minimum surface interval required between two dives to 60 feet for 30 minutes each, it's important to reference tables or computers used in scuba diving planning that outline no-decompression limits and surface interval recommendations.

When planning the dives, the first dive to 60 feet for 30 minutes will result in a certain amount of nitrogen absorption into the body, which needs to be off-gassed or eliminated during the surface interval before the second dive to the same depth and duration. The surface interval allows for this off-gassing, as well as reducing the risk of decompression sickness.

The specific surface interval needed is calculated based on the dive profile and the nitrogen loading from the first dive. According to common tables and dive computer algorithms, after performing a dive that has put you at a certain nitrogen level, the recommended minimum surface interval to safely proceed with a second dive of the same depth and duration usually exceeds a short or moderate surface interval.

Given the depth of 60 feet and the time spent there, a 2:29 surface interval appropriately accounts for the nitrogen loading from the first dive, providing sufficient time for the body to off-gas before entering the water again. This interval is essential in ensuring that safety limits are respected, as shorter intervals