Which of the following is true about navigation lights?

Navigation lights play a crucial role in ensuring the safety of vessels on the water, especially during low visibility conditions such as at night or in fog. The requirement to display navigation lights at all times after sunset is in accordance with maritime regulations, which dictate that vessels must be identifiable to avoid collisions when visibility is reduced.

When navigation lights are displayed, they help other vessels understand the type, size, and heading of the boat. For example, the arrangement and colors of the lights indicate whether a vessel is underway, anchored, or approaching. This is vital for maintaining safe navigation practices and preventing accidents on the water.

The other options suggest misunderstandings about navigation light regulations. While it's true that navigation lights are not strictly required during daylight hours, they become essential at sunset when visibility decreases. Additionally, these lights must be visible to others to effectively serve their purpose; they cannot be limited to the operator’s viewpoint. Lastly, navigation lights are mandatory for almost all boats, and not just optional for smaller vessels, ensuring the safety of all on the water.