How should a vessel determine its windward side?

A vessel should determine its windward side by identifying the side opposite to where the mainsail is carried. In sailing terminology, the windward side refers to the side of the vessel that is facing the incoming wind. When a mainsail is set, it will be filled with wind on the side that it is rigged to. Therefore, the opposite side of the mainsail represents the windward side, as that is the direction from which the wind is coming.

Understanding this concept is crucial for safe navigation and maneuvering, particularly in avoiding collisions with other vessels. By knowing which side the wind is coming from, sailors can better position their vessel in relation to other boats and obstacles, ensuring they maintain proper course and control.