What is a significant concern when performing altitude dives?

The increased risk of Decompression Sickness (DCS) is a significant concern when performing altitude dives due to the effects of reduced ambient pressure at higher elevations. As divers ascend to altitudes above sea level, the atmospheric pressure decreases, which alters the behavior of nitrogen dissolved in the body. During a dive, nitrogen is absorbed by tissues at a rate dependent on the surrounding pressure. When a diver completes an ascent to altitude, the drop in pressure can lead to the formation of nitrogen bubbles in the body if sufficient decompression stops are not included in the dive profile.

This increase in the likelihood of DCS emphasizes the need for divers to understand and apply specific altitude diving protocols, utilize proper ascent rates, and adhere to diving tables or dive computers designed for altitude. Additionally, divers must also consider how altitude affects their overall physiology and the planning of their dive, including the need for proper hydration and monitoring, as altitude could further worsen the risk of DCS.

Other concerns, while they may impact safety during a dive, do not carry the same level of criticality as DCS in the context of altitude diving.