What is the light signal authorized by the Secretary of the Navy as an additional navigational light for a ship of war?

• A. Flashing amber beacon for submarines
• B. White all-round light
• C. Red over white
• D. Green flare

Answer: (A)

An extra navigational light on ships of war can be authorized by the Secretary of the Navy in order to indicate the presence or operation of submarines. The light chosen for this purpose is a flashing amber beacon, because amber flashing is distinct from the standard red, green, and white navigation lights and clearly signals a special condition to other vessels. This makes it easy to recognize and avoid confusion with ordinary navigation signals. The white all-round light is a standard requirement for most vessels, not an additional Navy-specific signal. The red-over-white arrangement and a green flare correspond to other signals or indicators and do not serve as the Navy’s authorized extra navigational light for submarines.