Final answer:
When you anchor your boat at night, it is important to display anchor lights for the safety of other vessels. The required anchor lights in the United States are a white light visible all around the horizon for vessels less than 50 meters, and a white light visible for 360 degrees for vessels more than 50 meters in length.
Step-by-step explanation:
When you have anchored your boat, there are specific lights that you are required to display at night for the safety of other vessels. These lights are known as anchor lights. In the United States, the anchor lights required to be displayed at night include a white light visible all around the horizon for vessels less than 50 meters, and a white light visible for 360 degrees for vessels more than 50 meters in length. The light should be placed where it can be seen without any obstruction. These anchor lights help other boats in the vicinity to identify and navigate around your anchored vessel.