SDI Open Water Scuba Diver Practice Exam 2026 - Free Scuba Diver Practice Questions and Study Guide

Nitrogen narcosis is a condition that divers may experience when diving at depths typically greater than 30 meters (100 feet). The phenomenon occurs due to the increased partial pressure of nitrogen, which is a major component of the air we breathe. As divers descend, the pressure surrounding them increases, leading to a higher concentration of nitrogen dissolved in their blood and tissues. This increased nitrogen can affect the central nervous system, resulting in symptoms akin to intoxication, such as impaired judgment, euphoria, and in some cases, confusion.

Understanding that this condition is primarily related to depth and the effects of pressure on nitrogen demonstrates why this particular answer is correct. The threshold of 30 meters (100 feet) is commonly recognized within the diving community as a point where divers are more likely to begin experiencing the effects of nitrogen narcosis.

The other choices deviate from this understanding. The suggestion that nitrogen narcosis can occur at any depth misrepresents the relationship between pressure and nitrogen effects. Additionally, labeling nitrogen narcosis as a psychological disorder or as a malfunction of diving equipment overlooks the physiological basis of the condition. Recognizing the specific association between nitrogen levels and depth is crucial for divers to manage their exposure and remain safe underwater.