Final answer:
Navigation lights are mandatory for sailboats over 23 feet when operating between sunset and sunrise, or in restricted visibility, to ensure safety and compliance with maritime laws.
Step-by-step explanation:
When operating a sailboat over 23 feet in length or 7 meters, there are specific navigation lights that must be displayed during the hours between sunset and sunrise, as well as during periods of restricted visibility such as fog. These lights help prevent collisions by allowing other vessels to see the sailboat from a distance. The requirement for these lights is not only a safety measure but also adheres to maritime regulations. Although the provided reference material discusses navigating by the sun and does not directly offer information about navigation lights, the content does highlight the importance of visibility and safety considerations when at sea.