What is the primary method of preventing narcosis during diving?

Diving at shallower depths is the primary method of preventing narcosis during diving because narcosis is largely caused by high partial pressures of nitrogen, which increases as depth increases. At greater depths, the amount of nitrogen that dissolves into the body's tissues rises, leading to the risk of nitrogen narcosis, which can impair cognitive and motor functions.

By choosing to dive at shallower depths, divers can significantly reduce their exposure to high partial pressures of nitrogen, thus minimizing the likelihood of experiencing narcosis. It is important for divers to monitor their depth and plan dives accordingly, particularly if they are susceptible to the effects of narcosis or are diving in conditions that may contribute to heightened stress or fatigue.

Using nitrogen-rich gas mixtures or increasing dive durations would not effectively prevent narcosis, as these factors would rather exacerbate the condition. Adjusting depth is a well-established preventive measure that enhances safety during dives.