What must be true about navigational lights used within 225 degrees?

Navigational lights are crucial for safe maritime operations, as they help communicate a vessel's position, heading, and activity to other vessels, especially in reduced visibility conditions. When it comes to lights used within an arc of 225 degrees, the requirement is that they must not show through an arc of more than 225 degrees, which means that their visibility is restricted to ensure clarity in communication at sea.

This restriction is important to prevent confusion among vessels. If a light were to show over a wider arc, it could mislead nearby vessels about the actual position or heading of the vessel displaying the lights. By restricting the light to within 225 degrees, it ensures that the navigational intent is clear and minimizes the risk of accidents.

In contrast, navigational lights must adhere to specific colors and flashing patterns designed for various types of vessels and their activities. Therefore, a continuous flash or any color for lights within that arc is not permissible, as it could convey incorrect information to other navigators. This helps maintain safety and effective communication on the water, which is why the requirement of the arc limitation is emphasized in maritime regulations.