What is the surface interval time needed to eliminate residual nitrogen after a Nitrox 36 dive to 30 meters for 40 minutes?

To determine the appropriate surface interval time needed to eliminate residual nitrogen following a Nitrox 36 dive to 30 meters for 40 minutes, it is essential to understand how Nitrox (an oxygen-enriched air mixture) impacts nitrogen absorption during dives and the subsequent off-gassing process.

After a dive, the body will retain some nitrogen based on the depth and duration you were underwater. The purpose of a surface interval is to allow sufficient time for this nitrogen to be safely eliminated from the body before the next dive. The recommended surface interval depends on various factors, including the dive profile and the mix of gases used.

In the case of Nitrox 36, which contains 36% oxygen and 64% nitrogen, a dive to 30 meters for 40 minutes will result in a specific amount of nitrogen being absorbed. Generally, dive tables or dive computers help calculate the necessary surface interval to clear residual nitrogen, accounting for factors like the partial pressure of nitrogen at depth and dive duration.

The answer of 45-60 minutes is consistent with general guidelines for surface intervals following a dive of this nature. At a maximum depth and duration of the specified dive, a 45-60 minute surface interval is typically sufficient to allow the body to off-g