Why do scuba divers tend to become dehydrated while diving?

Scuba divers tend to become dehydrated primarily because of the dry inhaled air during dives. When divers breathe compressed air from tanks, it is often drier than the air they would normally breathe on the surface. This can lead to moisture being pulled from the body's tissues, contributing to dehydration. The lungs absorb moisture from the breathing air, and the breathing gas's low humidity can increase fluid loss.

In addition to the environmental factors, the depth and duration of dives can also increase the body's fluid requirements. While all divers should be aware of hydration, the specific impact of dry inhaled air on moisture levels is a significant contributor to dehydration during dives, making this the most relevant choice in the context of scuba diving.