Question 18

The Correct Answer is A **Explanation for Option A (A vessel constrained by her draft):** Rule 28 of the COLREGs (International Regulations for Preventing Collisions at Sea) specifies the lights and shapes for vessels constrained by their draft (CBD). A vessel constrained by her draft must display, in addition to the lights required for a power-driven vessel of her length, three all-round red lights in a vertical line where they can best be seen. Therefore, a vessel displaying three red lights in a vertical line, dead ahead at night, is a vessel constrained by her draft. **Explanation of Incorrect Options:** **B) A vessel moored over a wreck:** A vessel engaged in diving or underwater operations (which includes being moored over a wreck, depending on the activity) displays three all-round lights in a vertical line: Red, White, Red. This differs from the three all-round red lights. **C) A vessel aground:** A vessel aground displays the lights of a vessel at anchor (the forward and aft anchor lights) and, in addition, where they can best be seen, two all-round red lights in a vertical line. This is two red lights, not three. **D) A vessel dredging:** A vessel engaged in dredging or underwater operations displays lights to indicate the side on which the obstruction exists (two all-round red lights) and the side on which another vessel may pass (two all-round green lights), in addition to the masthead, sidelights, and sternlight for a power-driven vessel. It does not display three all-round red lights in a single vertical line to indicate its activity.