Question 32
ONC04BOTH INTERNATIONAL & INLAND Which of the following describes a vessel exhibiting the lights shown in illustration D084RR below?

AI Explanation
The Correct Answer is A.
### Explanation for Option A (Correct Answer)
The illustration D084RR depicts a vessel showing two **all-round red lights** displayed one vertically above the other.
According to both the International Regulations for Preventing Collisions at Sea (COLREGs) Rule 27(b) and the Inland Rules (corresponding sections), a vessel that is **not under command (NUC)** must exhibit these specific lights:
1. **Two all-round red lights** in a vertical line, where they can best be seen. (The meaning is "Red over Red, the Captain is Dead" or "Restricted ability to maneuver/control.")
2. When making way through the water, it must also show sidelights and a sternlight. (The illustration usually focuses on the primary NUC signal.)
Therefore, the lights shown specifically identify a vessel that is **not under command**.
### Explanations for Incorrect Options
**B) showing improper lights:** The lights shown (two vertical all-round red lights) are prescribed signals defined by the rules. They are being shown exactly as required to indicate a specific status (Not Under Command). Therefore, the lights are proper, not improper.
**C) dredging:** A vessel engaged in dredging (or underwater operations, Restricted in Her Ability to Maneuver - RAM) typically displays:
* Three all-round lights in a vertical line: Red-White-Red (Rule 27(b)).
* When an obstruction exists, it must show two all-round red lights on the side of the obstruction and two all-round green lights on the side where another vessel may pass (Rule 27(d)).
The lights shown (two vertical red lights) do not meet the requirements for a vessel engaged in dredging.
**D) towing:** A vessel engaged in towing shows specific masthead lights related to the length of the tow:
* Towing (tow less than 200m): Two masthead lights in a vertical line, plus sidelights and a sternlight.
* Towing (tow greater than 200m): Three masthead lights in a vertical line, plus sidelights and a sternlight.
It does **not** show two vertical all-round red lights, which are reserved for Not Under Command (NUC) or anchoring signals (in some niche contexts, but not as the primary indication of towing).