Which statement best describes the surface interval?

Which statement best describes the surface interval?

• A. Time spent at depth during a dive
• B. Time spent at the surface between dives
• C. Time required for a decompression stop
• D. Time under water during a dive

Answer: (B)

Surface interval is the time spent on the surface between dives. It lets the inert gas (mostly nitrogen) that dissolved in your tissues during the dive off‑gas, reducing the overall nitrogen load for the next dive. The longer the surface interval, the more off-gassing occurs, which helps lower the risk of decompression sickness when you resume diving. It’s not about time spent at depth (bottom time), not the time you’re underwater, and not the decompression stop time that may be required during ascent.

Surface interval is the time spent on the surface between dives. It lets the inert gas (mostly nitrogen) that dissolved in your tissues during the dive off‑gas, reducing the overall nitrogen load for the next dive. The longer the surface interval, the more off-gassing occurs, which helps lower the risk of decompression sickness when you resume diving. It’s not about time spent at depth (bottom time), not the time you’re underwater, and not the decompression stop time that may be required during ascent.