Beginner Scuba Certification Practice Test 2026 - Free Scuba Certification Practice Questions and Study Guide

To determine the residual nitrogen time for a diver with a group letter of 'F' after making a dive to 60 feet, it is essential to understand how dive tables and residual nitrogen times work.

The group letter system is a standardized way of representing a diver's residual nitrogen level and is closely tied to the depths and durations of previous dives. Each group letter corresponds to a specific residual nitrogen time based on the depth and time spent at that depth.

In this case, if the diver is at 60 feet and has a group letter of 'F,' the associated residual nitrogen time is 36 minutes. This means that after completing the dive, this diver’s body has absorbed a certain amount of nitrogen, which will still be present for an additional 36 minutes before it clears from the system.

Understanding this concept is crucial for divers to avoid decompression sickness when conducting multiple dives within a short period. Residual nitrogen times play an important role in planning subsequent dives and ensuring a safe diving experience.