Question 30

The Correct Answer is C **Explanation for Option C (sailing vessel):** The illustration D080RR shows a vessel displaying **red over green** vertical lights. According to the U.S. Inland and International Rules of the Road (33 CFR Subchapter E, specifically Rule 25), a power-driven vessel underway must exhibit sidelights and a sternlight, and a masthead light (or two). A sailing vessel underway is required to exhibit sidelights and a sternlight, but is *permitted* to exhibit the all-round **red over green** vertical lights instead of the standard sidelights and sternlight. Therefore, seeing only the red over green lights indicates a vessel utilizing the optional lighting arrangement for a **sailing vessel** underway. **Explanation of Incorrect Options:** * **A) vessel on pilotage duty:** A vessel engaged in pilotage duty displays **white over red** vertical all-round lights (Pilot preceding power). * **B) law enforcement vessel:** While law enforcement vessels may display special flashing blue lights, their primary navigation lights must still conform to the rules for a power-driven vessel, which does not include the standard display of red over green lights as the sole visible illumination (unless they happen to be a sailing vessel). * **D) vessel engaged in fishing:** A vessel engaged in fishing (trawling or otherwise) displays **green over white** vertical all-round lights (Trawling preceding fishing, but generally green over white for fishing).