What is the arc of a 'special flashing light'?

The arc of a 'special flashing light' is defined as being not less than 180 degrees nor more than 225 degrees. This specification is crucial because it helps ensure that the visibility of the light is adequate to communicate specific information to other vessels or entities. The arc is designed to cover a significant portion of the horizon to alert nearby vessels effectively, particularly in situations where a vessel may be exhibiting behavior or characteristics that require attention.

A 'special flashing light' serves a particular function, and the defined arc restrictions ensure that the light serves its purpose without misleading or confusing other navigators. These parameters are laid out in the COLREGs to promote clarity and safety in navigation practices, ensuring that lights can be seen reliably from various angles depending on the circumstances, such as during the night or in low-visibility conditions. Thus, the specific range of not less than 180 degrees nor more than 225 degrees establishes a standard for the operational use and recognition of these lights, aligning with international maritime safety standards.