Question 4 RVR04 - Master or Mate of LT 200 GRT

The Correct Answer is C **Explanation for Option C (Correct Answer):** The lighting configuration described – seeing both red and green sidelights (indicating a power-driven vessel underway and viewed from ahead) plus three white lights in a vertical line above the level of the sidelights – specifically corresponds to the requirements under the COLREGs (International Regulations for Preventing Collisions at Sea) for a vessel engaged in towing. * **Towing Lights:** Rule 21(a)(ii) and Rule 24(a) require a vessel towing to show two or three masthead lights in a vertical line instead of the usual single masthead light (or two if over 50m). * **Significance of Three White Lights:** When the length of the tow (measured from the stern of the towing vessel to the after end of the tow) exceeds 200 meters, the towing vessel must display **three** white masthead lights in a vertical line (COLREG Rule 24(a)(ii)). * **Visibility:** Since the observer sees the red and green sidelights, they are viewing the vessel from dead ahead or nearly ahead, confirming it is the towing vessel itself displaying the required three vertical white lights due to the long tow. **Explanation for Why Other Options Are Incorrect:** * **A) a vessel not under command (NUC):** A vessel not under command (Rule 27(a)) displays **two** all-round red lights in a vertical line where masthead lights would typically be, and not three white lights. * **B) a vessel trawling:** A vessel engaged in fishing (trawling, specifically, according to Rule 26(b)) displays **two** lights in a vertical line: an all-round **green** light over an all-round **white** light. It does not display three vertical white lights. * **D) a vessel underway and dredging:** A vessel engaged in dredging (Rule 27(d)) displays the lights for a vessel restricted in its ability to maneuver (three all-round lights: Red-White-Red in a vertical line) or specific lights related to obstructing the channel. It does not display three vertical white masthead lights.