According to SSI Training Standards, what height above sea level classifies diving at altitude?

Diving at altitude is classified as occurring above 1,000 feet (or approximately 300 meters) above sea level. This classification is important because as altitude increases, the atmospheric pressure decreases, which can significantly affect gas absorption and the risk of decompression sickness.

At elevations above this threshold, divers must consider the physiological changes that occur in their bodies and how they affect diving practices. For instance, the reduced pressure at higher altitudes can lead to a higher likelihood of nitrogen obtaining a "supersaturated" state in body tissues during a dive. It also necessitates the use of specific dive tables or dive computers that account for altitude to ensure safe diving procedures and proper ascent rates.

Understanding this classification helps divers prepare adequately for the unique challenges posed by altitude diving, such as potential altitude sickness and the need for specific dive planning and training.