For an anchored vessel greater than or equal to 100 meters, which description correctly states the lighting requirement?

• A. One light
• B. Two lights, plus her decks should be illuminated
• C. Two lights
• D. Three lights

Answer: (B)

When a vessel is at anchor, a white anchor light must be shown. For vessels that are 100 meters or longer, regulations require two white lights in a vertical line to mark the vessel’s length and orientation—one forward and one aft—so other mariners can clearly see the vessel's size and position at night. In addition, decks should be illuminated if practical, to further reveal the vessel’s presence and overall silhouette.

So the best description is two lights plus deck illumination, which matches the requirement for large anchored vessels. The other options don’t meet the full rule: a single light isn’t enough for a vessel of this length, two lights without deck illumination omits the additional visibility, and three lights exceed the specified requirement.