What is the recommended action for nitrogen narcosis when symptoms are present?

• A. Ascend to shallower depth and place on 100% O2
• B. Continue the dive and monitor symptoms
• C. Descend deeper to counteract narcosis
• D. Ignore symptoms

Answer: (C)

Nitrogen narcosis comes from increased nitrogen partial pressure at depth, which depresses mental function and can impair judgment and coordination. When symptoms appear, the quickest way to relieve them is to ascend to a shallower depth where the nitrogen pressure is lower, allowing narcosis to subside. If you’re at a depth where it’s safe to do so, you can also use 100% oxygen at a shallow depth or on the surface to speed up nitrogen off-gassing and recovery. Descending deeper would raise the nitrogen pressure and typically worsen the symptoms, and ignoring or continuing the dive while narcosis is present increases the risk of errors or an emergency. So the recommended action is to ascend to a shallower depth and use oxygen as appropriate to hasten recovery.