In scuba diving, what should you do if you suspect a fellow diver is experiencing Nitrogen Narcosis?

If you suspect a fellow diver is experiencing Nitrogen Narcosis, the most appropriate action is to assist them in an immediate ascent to the surface while ensuring a controlled ascent. Nitrogen Narcosis, often referred to as "the bends," can significantly impair a diver's mental function and decision-making abilities, potentially putting them in dangerous situations. Ascending to shallower depths is crucial because nitrogen narcosis symptoms tend to diminish with decreasing depth.

It is essential for the diver to reach a depth where the effects of the nitrogen narcosis are reduced or eliminated. This change in pressure aids in reducing narcosis symptoms, allowing for better mental clarity. During the ascent, maintaining a slow and controlled rise is important to prevent other risks, such as decompression sickness, but prioritizing getting the diver away from the deeper depths where narcosis is most potent is paramount.

Other choices, such as encouraging the diver to ascend slowly or staying at greater depths, do not address the immediate need to alleviate the symptoms of nitrogen narcosis effectively. Providing additional weights would further complicate the situation, potentially leading to other safety issues.