Coast Guard Exams

Question 42

RVR02

BOTH INTERNATIONAL & INLAND Which lights is a vessel not under command, underway but not making way, required to exhibit?

AI Explanation
The Correct Answer is A. **Explanation for Option A (Correct):** Rule 27(a)(i) of the International Regulations for Preventing Collisions at Sea (COLREGs), which applies to both international and inland waters, specifies the lights required for a vessel "not under command" (NUC). A vessel NUC, regardless of whether it is underway or making way, is required to exhibit **two all-round red lights in a vertical line** where they can best be seen. These lights indicate the vessel's inability to maneuver as required by the Rules. **Explanation for Options B, C, and D (Incorrect in isolation/as a primary answer):** * **B) a stern light:** While a vessel NUC that is underway must exhibit a stern light (Rule 27(a)(ii) and Rule 23), the defining characteristic lights for an NUC vessel are the two all-round red lights. Furthermore, the question asks what lights the vessel is *required* to exhibit. If the vessel is underway but *not making way*, it is not required to show the sidelights and the stern light (though Rule 27(a)(ii) technically requires the lights of a vessel underway). However, even if the vessel *was* underway and making way, the presence of the navigation lights (stern and sidelights) is secondary to the primary signal of distress/disability, which is the two all-round red lights. Therefore, "two all-round red lights" is the mandatory and specific answer for the NUC status. * **C) sidelights:** Similar to the stern light, sidelights (required under Rule 27(a)(ii) and Rule 23) are standard navigation lights. However, Rule 27(a)(ii) requires the normal masthead lights, sidelights, and stern light *only if the vessel is making way*. Since the vessel in the question is "underway but **not making way**," it is **not** required to exhibit the sidelights (or the stern light/masthead light). It *is* always required to show the two all-round red lights (Rule 27(a)(i)). * **D) All of the above:** This is incorrect because the vessel is "not making way," meaning it is not required to exhibit the sidelights (C) and the stern light (B). Only the two all-round red lights (A) are mandatory in this specific condition for indicating the NUC status.