What is one common effect of alcohol on boat operators?

Alcohol consumption significantly impairs cognitive and physical functions, which directly affects a boat operator's ability to judge distances accurately. When operating a vessel, precise distance estimation is crucial for safe navigation, docking, and maneuvering around obstacles or other vessels. The impairments caused by alcohol can lead to a miscalculation of distance, potentially resulting in collisions or accidents. Given the complexities of operating a boat, including the need to assess speed, distance, and proximity to other objects, the inability to judge distances correctly poses a serious risk to both the operator and others on the water.

In contrast, the other options suggest effects that are contrary to how alcohol typically influences performance. For example, alcohol does not enhance decision-making skills; rather, it often leads to poor judgment and riskier behavior. Similarly, reaction times tend to slow down rather than improve, and alertness decreases as a result of alcohol consumption. These impairments highlight the critical importance of understanding the detrimental effects of alcohol on boating safety.