At what depth do symptoms of nitrogen narcosis typically become prominent?

The onset of nitrogen narcosis typically becomes prominent around 130 feet of seawater (fsw). At this depth, divers may start to experience alterations in mental status and cognitive function due to the effects of nitrogen under pressure. The phenomenon is often likened to the feeling of being slightly intoxicated, characterized by impaired judgment and motor skills.

As divers descend deeper, the risk of nitrogen narcosis increases, with symptoms varying based on individual susceptibility, rate of descent, and the total time spent at depth. Recognizing the typical depth of onset at 130 fsw is crucial for divers and supervisors, as it allows for appropriate planning, dive profiles, and safety measures to mitigate the risks associated with narcosis. Understanding this aspect of diving physiology helps in preparing divers for deeper dives and the potential challenges they may face.