Which activity is NOT a valid method of signaling distress?

Shouting into the wind does not serve as an effective method of signaling distress because noise travels less efficiently in windy conditions, making it hard for others to hear and locate the source of the distress. Effective distress signaling methods must be clear and noticeable, aiming to attract attention in a manner that can be easily interpreted by other vessels or rescue teams.

In contrast, signaling distress with a gunshot is recognized as a method to indicate trouble, particularly when repeated at intervals. The use of a square flag with a ball, known as the International Code Flag "N," is a recognized visual signal for distress. Creating visible flames on a vessel can also attract attention, serving as a signal for help due to the smoke and flames being easily visible from a distance. Each of these methods involves a clear message or an easily detectable signal that can alert others to a vessel in distress, while shouting does not meet those criteria effectively.