When is it required to have a signal flag on board?

The requirement to have a signal flag on board, particularly when operating in a vicinity with divers below the surface, is based on safety regulations designed to protect individuals who are diving. The signal flag serves as a clear indicator to other boaters that there are divers in the water, which is essential for preventing accidents. When the flag is displayed, it alerts nearby vessels to exercise caution, maintain a safe distance, and be vigilant while navigating in that area.

This precaution is crucial because divers are often submerged and may not be visible to boaters, increasing the risk of collisions. By ensuring that a signal flag is present, boat operators contribute to a safer environment for divers and promote adherence to maritime safety standards.

In contrast, having a signal flag is not specifically mandated for activities related to traveling in deep waters, fishing in restricted areas, or entering a crowded harbor, as these conditions do not directly pertain to the safety of divers.