What is the designated decompression requirement for a dive to 80 feet for 60 minutes?

The correct response highlights the importance of managing nitrogen absorption and off-gassing during dives, particularly for a dive of this depth and duration. When a diver spends 60 minutes at 80 feet, they are likely to exceed the no-decompression limits set for recreational diving, which makes decompression necessary to avoid nitrogen narcosis and decompression sickness.

Option C specifies a requirement of 1 minute at 20 feet followed by 28 minutes at 15 feet. This approach allows the diver adequate time to safely off-gas the absorbed nitrogen from the body. Ascending to 20 feet first helps to minimize pressure quickly, while the extended time at 15 feet further ensures that nitrogen levels are reduced to safe levels before reaching the surface.

In contrast, the other responses do not effectively address the necessary procedures after such a prolonged dive. Some suggest insufficient decompression time or put forth a sequence of depths and durations that are not suitable for safe ascent after a dive of this length, thereby increasing the risk of decompression sickness. Proper understanding of decompression schedules and adhering to them is crucial for diver safety, which is why Option C is the most appropriate choice.