Which distress signal involves waving arms?

The distress signal that involves waving arms is indeed the visual alert. This method is a universally recognized gesture indicating that someone is in need of assistance and can be easily spotted by others. When someone waves their arms, especially in a manner that is exaggerated or consistent, it catches the attention of nearby vessels or individuals, helping to clearly communicate the urgency of their situation.

Visual alerts can be particularly valuable in emergency situations when other means of communication, such as verbal signals or electronic devices, are not available. This method relies on the visibility of the person in distress, making it effective in both daytime and nighttime conditions, provided there is adequate lighting.

The other options, while important in distress signaling, do not involve the act of waving arms. A Mayday call refers to a vocal distress signal made using radio communication, while Emergency SOS typically involves specific signals like sound or light, often from devices designed to send such signals. Radio transmission conveys distress through electronic means, rather than visual gestures.