What is the primary reason to avoid alcohol before diving?

The primary reason to avoid alcohol before diving is that it impairs judgment and physical coordination. Alcohol affects the central nervous system, leading to reduced cognitive function, slower reaction times, and diminished decision-making abilities. When divers consume alcohol, they may underestimate risks, make poor choices, or react ineffectively to unexpected situations underwater, all of which can significantly compromise safety.

Diving requires a clear mind and good physical coordination to manage equipment, navigate underwater environments, and respond to emergencies. Alcohol consumption can lead to a false sense of confidence and relaxation, which may provide a deceptive sense of security, but ultimately detracts from the diver's ability to respond appropriately to challenges.

In contrast, while hydration is important for diving safety, alcohol does increase the risk of dehydration; however, this is not the primary concern immediately affecting a diver’s safety underwater. Other choices, such as enhancing lung capacity or improving relaxation and comfort, are not valid reasons related to pre-dive alcohol consumption, as these effects do not support or enhance a diver's performance or safety in the water.