Which of the following Navigation Lights are illuminated at night while in port?

Anchor lights are specifically designated lights that a vessel displays when it is anchored and not underway. These lights are typically illuminated at night to indicate the presence of the anchored vessel to others, ensuring safety within the port area. The anchor light is usually positioned at the highest point of the vessel and emits a white light that is visible from all directions.

In contrast, navigational beacons are fixed markers that guide vessels but are not part of the vessels' own lighting systems. Running lights are used when a vessel is underway, indicating the direction of travel, while search lights are for illuminating an area and are not continuously displayed as a navigation light. Thus, anchor lights serve the specific purpose of warning other vessels of an anchored ship, making them the correct answer in the context of the question regarding navigation lights used while in port at night.