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 CBD, when underway, must display the lights of a power-driven vessel of the same length, and in addition, must display **three all-round red lights in a vertical line**. These three all-round red lights indicate the vessel is unable to deviate from its course due to the limited depth and width of navigable water. **Explanation for Incorrect Options:** **B) A vessel moored over a wreck:** A vessel moored over a wreck (a vessel engaged in diving operations or similar restricted maneuverability) would display three all-round lights in a vertical line, but they would be **Red-White-Red** (R-W-R) to signify "restricted in her ability to maneuver." If the vessel is stationary, it would also display anchor lights. Three solid red lights (R-R-R) specifically identify a vessel constrained by its draft. **C) A vessel aground:** A vessel aground displays the lights for a vessel at anchor (forward all-round white light and/or aft all-round white light, depending on length), and in addition, displays **two all-round red lights in a vertical line** to indicate it is aground. It does not display three red lights. **D) A vessel dredging:** A vessel engaged in dredging (a vessel restricted in her ability to maneuver) displays the standard lights for a vessel restricted in her ability to maneuver (R-W-R), and when there is an obstruction, it displays **two all-round red lights** on the side where the obstruction exists and **two all-round green lights** on the side on which another vessel may pass. It does not display three solid red lights.