Under repetitive dives, how do no-decompression limits compare to single dives?

Under repetitive dives, how do no-decompression limits compare to single dives?

• A. Less conservative
• B. More conservative
• C. Significantly greater
• D. No change

Answer: (B)

No-decompression limits are reduced after a previous dive because residual nitrogen from the first dive remains in the tissues. That extra nitrogen means you’re closer to the decompression boundary, so the next dive at the same depth has a shorter no-decompression time. If you have a longer surface interval, this residual nitrogen off-gasses and the second dive’s NDL moves back toward the single-dive value; with a very short surface interval, it stays more conservative.

No-decompression limits are reduced after a previous dive because residual nitrogen from the first dive remains in the tissues. That extra nitrogen means you’re closer to the decompression boundary, so the next dive at the same depth has a shorter no-decompression time. If you have a longer surface interval, this residual nitrogen off-gasses and the second dive’s NDL moves back toward the single-dive value; with a very short surface interval, it stays more conservative.