Which of the following is a common indicator of poor weather while boating?

Darkening clouds and increasing wind are indeed common indicators of poor weather while boating. When you observe darkening clouds, it often suggests that a storm or significant weather system is approaching, which can bring rain, thunderstorms, or other adverse conditions. Increasing wind speed can also indicate that weather conditions are deteriorating, as strong winds can lead to rough water, making boating more hazardous.

In contrast, bright sunlight typically signifies clear weather, making it less likely to be a signal of poor conditions. Calm water conditions generally indicate stable weather, suggesting that there are no storms or high winds nearby. Persistent bird activity does not reliably indicate weather conditions; while some birds may react to changing weather, their presence alone is not a strong enough signal for impending poor weather. The combination of darkening clouds and rising winds serves as a critical warning for boaters to take appropriate precautions and seek safer conditions.