When should the rules concerning lights be complied with?

The correct understanding is that regulations concerning navigation lights must be adhered to from sunset to sunrise. This timeframe is critical because, during the hours of darkness, visibility is significantly reduced, making it essential for vessels to display their lights to indicate their presence, direction, and status to other vessels. The use of lights helps prevent collisions and ensures safe navigation when natural light is insufficient.

Compliance with these rules during nighttime is vital; however, it's important to remember that while navigation lights are primarily required from sunset to sunrise, vessels must also display lights during restricted visibility conditions, such as fog, heavy rain, or other adverse weather. Therefore, while the answer focuses on the nighttime aspect, the broader context includes the importance of maintaining visibility under all circumstances when conditions impair normal visibility.