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 (CBD). A CBD vessel shall exhibit, in addition to the lights prescribed for a power-driven vessel underway: 1. Three all-round red lights in a vertical line. 2. When underway, a masthead light (or lights), sidelights, and stern light. The three all-round red lights indicate the CBD status and are positioned where they can best be seen. **Explanation of Incorrect Options:** **B) A vessel moored over a wreck:** A vessel moored over a wreck engaged in underwater operations would typically be defined as a vessel restricted in her ability to maneuver (RAM). A vessel RAM displays three all-round lights in a vertical line: **red, white, red**. It does not display three red lights. If she is performing dredging or underwater operations, she may also indicate the side on which an obstruction exists (two all-round red lights) and the side on which another vessel may pass (two all-round green lights). **C) A vessel aground:** Rule 30(e) states that a vessel aground displays the lights for a vessel at anchor (an all-round white light forward, and one aft or otherwise two all-round white lights) and, in addition, **two all-round red lights** in a vertical line where they can best be seen. It does not display three red lights. **D) A vessel dredging:** A vessel dredging is considered a vessel restricted in her ability to maneuver (RAM) because of the nature of the operation. As explained in B, a RAM vessel displays three all-round lights: **red, white, red**. It does not display three red lights.