Lights must be used from ___________________ to _________________ and in times of restricted visibility.

The requirement for using lights on a vessel is primarily dictated by the rules established in the Navigation Rules, often referred to as the "Colregs." These rules specify that navigation lights must be displayed during the hours of darkness, which extends from sunset to sunrise. This ensures that vessels can be easily seen by other vessels and helps to prevent collisions.

Additionally, the use of lights is mandated during times of restricted visibility, such as fog, heavy rain, or other environmental conditions that limit visibility. This is to enhance safety on the water by ensuring that all vessels are aware of each other's presence even when visibility is compromised. Thus, the correct answer emphasizes the importance of lighting as a critical safety measure in both low-light conditions and adverse weather, aligning with established maritime safety practices.