Question 4 RVR01 - Master of Unlimited Tonnage

The Correct Answer is C **Explanation for Option C (Correct Answer):** Option C, "a vessel towing a tow more than 200 meters astern," is correct based on the International Regulations for Preventing Collisions at Sea (COLREGs), Rule 24 and Rule 21. * **Vessel Towing:** A power-driven vessel that is towing displays the standard navigation lights (red and green sidelights) and masthead lights. * **Lights for Towing:** Rule 24 requires a towing vessel to show special masthead lights depending on the length of the tow: * One towing vessel shows two masthead lights in a vertical line (instead of the usual one or two for a typical power-driven vessel). * If the length of the tow (measured from the stern of the towing vessel to the after end of the tow) exceeds 200 meters, the vessel must display **three masthead lights** in a vertical line. * **The Observed Lights:** The observed lights are "red and green sidelights" (indicating a vessel underway) and "three white lights in a vertical line" above the sidelights (indicating a special status, specifically a tow exceeding 200 meters). These three white lights serve as the required masthead lights. **Explanation of Incorrect Options:** **A) a vessel not under command:** A vessel not under command (NUC) displays two all-round red lights in a vertical line where it can best be seen, along with sidelights and stern light when making way. It does **not** display three white lights in a vertical line. **B) a vessel trawling:** A vessel engaged in trawling displays two lights in a vertical line: the upper light being green and the lower light being white (all-round lights). It also displays the standard sidelights and stern light when underway. It does **not** display three white lights in a vertical line. **D) a vessel underway and dredging:** A vessel engaged in dredging displays different specific lights based on whether there is an obstruction. It typically displays three all-round lights in a vertical line (red-white-red), along with sidelights and stern light if underway. If there is an obstruction, it uses two all-round red lights to show the obstructed side and two all-round green lights to show the side where other vessels may pass. It does **not** use three white lights in a vertical line as its primary identifying signal.