What is the letter group designation after a dive to 60 feet for 30 minutes?

The correct choice for the letter group designation after a dive to 60 feet for 30 minutes is determined by utilizing the dive tables or dive computer to assess the residual nitrogen levels in the body following the dive. In this particular case, a dive to a depth of 60 feet for 30 minutes can be correlated to a specific letter group based on the nitrogen absorption and release indicated in the tables.

After completing the dive and allowing for appropriate surface intervals, the diver's residual nitrogen level is calculated, which typically falls into the 'C' letter group. This designation indicates that the diver is at a certain level of nitrogen being off-gassed, which is crucial for planning subsequent dives safely while avoiding decompression sickness. Understanding how diving profiles affect nitrogen buildup and what letter group corresponds to those profiles helps divers manage their dive plans effectively.