Question 18

The Correct Answer is A. **Explanation for A (A vessel constrained by her draft):** Rule 28(b) of the International Regulations for Preventing Collisions at Sea (COLREGs) specifies the lights for a vessel constrained by her draft (VCD). A VCD shall exhibit the lights prescribed for a power-driven vessel underway (masthead lights forward and aft, sidelights, and a sternlight), and additionally, **three all-round red lights in a vertical line**. These three red lights indicate the vessel's restricted ability to deviate from her course due to her draft. **Explanation for B (A vessel moored over a wreck):** A vessel moored over a wreck that is engaged in underwater operations (like a diving vessel) would typically display the lights for a vessel restricted in her ability to maneuver (three all-round lights in a vertical line: Red-White-Red). A simple vessel "moored over a wreck" that is not actively engaged in operations might just display anchor lights if at anchor, or nothing special if simply moored alongside another structure. It would not display three all-round red lights. **Explanation for C (A vessel aground):** Rule 30(h) specifies the lights for a vessel aground. A vessel aground shall exhibit the lights prescribed for a vessel at anchor (an all-round white light or lights), and additionally, **two all-round red lights in a vertical line**. (Not three). **Explanation for D (A vessel dredging):** Dredging is an operation that restricts a vessel's ability to maneuver. A vessel restricted in her ability to maneuver (RAM) must display three all-round lights in a vertical line: **Red-White-Red** (Rule 27(b)). Furthermore, if dredging or underwater operations make it hazardous for another vessel to pass on one or both sides, the vessel should display additional lights to indicate the obstruction (two all-round red lights on the side(s) of the obstruction, and two all-round green lights on the side(s) safe for passage). However, the primary identification lights for a RAM vessel are R-W-R, not three all-round red lights.