During the day, what signal is used to indicate a good place to land for someone in distress?

The signal used to indicate a good place to land for someone in distress during the day involves the vertical motion of a white flag or arms being raised and lowered. This specific gesture is universally recognized as a distress signal, aiming to attract the attention of nearby vessels or rescuers. The vertical motion signifies urgency and is easily visible from a distance, making it effective in conveying a message of needing assistance or safety.

In situations where someone is in distress on the water, the ability to communicate effectively can be a matter of life and death, and this particular method stands out due to its simplicity and clear visibility against various backgrounds. Other signals, while used in various contexts, do not convey the same immediate message of a safe landing spot for rescue.