What is the minimum length of a power-driven vessel that must show forward and after masthead lights?

What is the minimum length of a power-driven vessel that must show forward and after masthead lights?

• A. 50
• B. 20
• C. 12
• D. 100

Answer: (A)

In the COLREGS light rules, a power-driven vessel underway must display a white masthead light forward, and if the vessel is 50 meters or more in length, it must also show a second masthead light abaft of and higher than the forward one. This two-masthead arrangement helps other mariners gauge the vessel’s size and position at night. Therefore, the minimum length that requires both forward and after masthead lights is 50 meters. Shorter vessels still use only the forward masthead light along with the usual sidelights and stern light. A vessel that is 100 meters would also need two masthead lights, but the question asks for the smallest length that triggers the requirement.

In the COLREGS light rules, a power-driven vessel underway must display a white masthead light forward, and if the vessel is 50 meters or more in length, it must also show a second masthead light abaft of and higher than the forward one. This two-masthead arrangement helps other mariners gauge the vessel’s size and position at night. Therefore, the minimum length that requires both forward and after masthead lights is 50 meters. Shorter vessels still use only the forward masthead light along with the usual sidelights and stern light. A vessel that is 100 meters would also need two masthead lights, but the question asks for the smallest length that triggers the requirement.