Which light signals a vessel that is both anchored and greater than 50 meters?

Answer: A — second all-around light

The appropriate light signal for a vessel that is both anchored and exceeds 50 meters in length is a second all-around light. According to the COLREGs, vessels over this length are required to display additional visual signals to enhance their visibility and indicate their status to other vessels. In this case, the second all-around light is positioned vertically above the first, helping to clearly signal that the vessel is not under way and is instead at anchor. This regulation is essential for promoting safety at sea, allowing other mariners to quickly and accurately identify the vessel’s status even in poor visibility conditions. Other light options listed do not meet the specific requirements set forth in the COLREGs for vessels of this size and condition, making the choice of adding a second all-around light the correct and necessary protocol for large vessels at anchor.