While underway at night you are coming up on a vessel from astern. Which light(s) would you expect to see?

While underway at night you are coming up on a vessel from astern. Which light(s) would you expect to see?

• A. Sternlight
• B. Sidelights
• C. Masthead lights
• D. All-round white light

Answer: (A)

The key idea is the directionality of navigation lights. The sternlight is placed at the stern and shines aft, so it’s the light you’d expect to see when approaching a vessel from its rear. Sidelights and masthead lights light forward and are aimed to be seen from ahead or the sides, not from behind, so they wouldn’t be visible from an approaching position. An all-round white light is used when a vessel is not underway (e.g., at anchor or aground), which isn’t the scenario here. So, from astern, the sternlight is the light you would see.

The key idea is the directionality of navigation lights. The sternlight is placed at the stern and shines aft, so it’s the light you’d expect to see when approaching a vessel from its rear. Sidelights and masthead lights light forward and are aimed to be seen from ahead or the sides, not from behind, so they wouldn’t be visible from an approaching position. An all-round white light is used when a vessel is not underway (e.g., at anchor or aground), which isn’t the scenario here. So, from astern, the sternlight is the light you would see.