What is the "rule of threes" in diving emergencies?

The "rule of threes" in diving emergencies provides a framework for understanding the critical time limits for survival in life-threatening situations. The correct answer outlines that a diver can survive three minutes without air, three hours without shelter, and three days without water.

Understanding this rule is crucial for divers because it helps them prioritize their actions during emergencies, such as ascending properly to ensure they can breathe and focusing on getting to shelter or safety when needed.

For instance, survival without air is the most pressing concern, as the lack of oxygen will quickly lead to unconsciousness and death. Following this, exposure to the elements can become life-threatening within three hours, especially in cold water or extreme weather conditions. Lastly, while water is essential for survival, humans can typically last three days without it, which prioritizes action related to finding air and shelter first. This hierarchy of needs is fundamental in emergency response scenarios related to diving.