Question 32 ONC03 - Master LT 500-1600 GRT

The Correct Answer is A. ### Why Option A ("not under command") is Correct Option A is correct because the illustration (D084RR) shows a vessel displaying **two all-round red lights**, one vertically above the other. According to Rule 27(a) of both the International Regulations for Preventing Collisions at Sea (COLREGs) and Inland Rules (US Inland Navigation Rules), a vessel **not under command (NUC)** must exhibit these two all-round red lights in a vertical line, where they can best be seen. ### Why Other Options Are Incorrect **B) showing improper lights:** This option is incorrect because the lights shown (two vertical all-round red lights) are prescribed lights for a specific circumstance (NUC) and are therefore not inherently improper, provided the vessel is actually unable to maneuver as required by the rules. **C) dredging:** This option is incorrect. A vessel engaged in dredging or underwater operations displays lights indicating it is "restricted in its ability to maneuver" (RAM). A RAM vessel shows three vertical lights: red-white-red. If the vessel is also restricted by its depth/draft, it may show three vertical red lights, but the primary indicator for dredging as a RAM vessel is the red-white-red sequence. Two vertical red lights specifically indicate NUC. **D) towing:** This option is incorrect. A power-driven vessel engaged in towing (other than short towing) typically shows two masthead lights in a vertical line, in addition to its sidelights and stern light, and a towing light above the stern light. Two vertical all-round red lights are never the required lights for a vessel simply engaged in towing.