Question 32 OSV01 - Master/Chief Mate - Offshore Supply Vessels

The Correct Answer is A ### Explanation for Option A (not under command) A vessel **not under command (NUC)**, as defined in Rule 27(a), must display two all-round red lights in a vertical line where they can best be seen. The illustration D084RR depicts this exact signal (two vertical all-round red lights). This configuration is the international and inland signal specifically reserved for a vessel that, due to some exceptional circumstance, is unable to maneuver as required by the Rules and is therefore unable to keep out of the way of another vessel. *** ### Explanation of Incorrect Options **B) showing improper lights** The lights displayed (two vertical all-round red lights) are proper lights, as they clearly and correctly indicate the internationally recognized status of a vessel "not under command." **C) dredging** Vessels engaged in dredging (or underwater operations, Rule 27(d)) typically exhibit three vertical lights: red-white-red (R-W-R), signifying a vessel restricted in its ability to maneuver. While the obstructed side of a dredging operation *may* be marked by two vertical red lights, the primary and complete signal displayed by only two vertical red lights is "Not Under Command." **D) towing** A vessel engaged in towing (Rule 24) must exhibit specific masthead lights (two or three in a vertical line, depending on the length of the tow) and a yellow towing light positioned above the stern light. It does not use two vertical all-round red lights as its defining characteristic.