Question 32 ONC05 - Master or Mate of LT 200 GRT

The Correct Answer is A. ### Explanation for Option A (Correct Answer) Option A, **"not under command"**, is correct because the illustration D084RR depicts a vessel exhibiting two vertical masthead lights that are **all-round red lights**. According to the International Regulations for Preventing Collisions at Sea (COLREGs), Rule 27(a), a vessel **"not under command" (NUC)** must exhibit: 1. **Two all-round red lights in a vertical line** where they can best be seen. (These lights are shown in the illustration). 2. When making way through the water, she must also exhibit sidelights and a sternlight. (The illustration generally focuses on the distinctive vertical identification lights). Therefore, the presence of the two vertical all-round red lights signifies a vessel that, through some exceptional circumstance, is unable to maneuver as required by the Rules and is, by definition, "not under command." --- ### Explanation of Incorrect Options **B) showing improper lights:** This is incorrect. The lights shown (two vertical all-round red lights) are prescribed and proper lights specifically for a vessel designated as "not under command" under Rule 27(a). **C) dredging:** This is incorrect. A vessel engaged in **dredging** (or underwater operations) must display three vertical all-round lights: Red-White-Red (R-W-R). The illustration shows only two red lights (R-R), which is not the signal for dredging. **D) towing:** This is incorrect. A vessel engaged in **towing** must display two (or three, depending on the tow length) vertical masthead lights (white lights), plus the required sidelights and sternlight, and a yellow towing light above the sternlight. The illustration shows red lights, which are never used as the primary identification lights for a vessel simply engaged in a normal towing operation.