What is the primary purpose of surface intervals between dives?

The primary purpose of surface intervals between dives is to allow nitrogen to off-gas. When divers breathe compressed air while underwater, they absorb nitrogen into their bodies. If divers do not allow sufficient time for this nitrogen to safely exit their bodies, it can lead to decompression sickness, commonly known as "the bends." Surface intervals provide the body with the necessary time to off-gas nitrogen, thus reducing the risk of this potential injury.

While practicing diving skills, socializing with other divers, and staying hydrated are all beneficial activities during surface intervals, they do not serve the critical safety function associated with off-gassing nitrogen. The focus on safety and health during these intervals is paramount to ensure that divers can continue to enjoy the sport without the risk of serious complications.