Question 50 GLI08 - Limited OUPV

The Correct Answer is B **Explanation for Option B (a sailing vessel underway):** The International Regulations for Preventing Collisions at Sea (COLREGs), which apply to both international and inland waters in the U.S. (via the Inland Rules), specify the navigation lights for various vessels. A vessel underway powered by sail must display side lights (red on port, green on starboard) and a stern light (white). If you sight a vessel displaying only a **single green light**, it indicates you are looking at the **starboard (right) side** of that vessel. A sailing vessel underway displays this configuration of lights. Therefore, sighting a single green light means you have sighted the starboard side of a sailing vessel underway. **Why the other options are incorrect:** * **A) a small motorboat underway:** A motorboat underway must display side lights (red and green) and a stern light (white). Additionally, if it is less than 50 meters in length, it must display an all-round white light or a masthead light forward and a stern light. Seeing only a single green light would only indicate the starboard side light, but the required white lights would be missing from this description if it were a motorboat. * **C) a vessel at anchor:** A vessel at anchor must display all-round white lights (one forward if less than 50 meters, two if 50 meters or more). It does not display colored side lights (red or green) while anchored. * **D) a vessel drifting:** A vessel that is drifting but not attached to the bottom or tied up is considered "underway." If it is powered by machinery, it is a power-driven vessel. If it is not using machinery and is under sail, it is a sailing vessel. If it is defined as a sailing vessel (like B), then the description fits. However, if it is a power-driven vessel that has shut off its engine, it must still display the lights of a power-driven vessel underway (including white lights). Since the single green light is specifically the required light configuration seen from the starboard side of a **sailing vessel**, this is the most accurate and complete answer, ruling out a general "drifting" vessel which could potentially be a power-driven vessel.