Which type of light is required on all power-driven vessels?

The correct type of light required on all power-driven vessels is the masthead light. This light is a crucial component of navigation safety, as it is designed to indicate the presence and direction of a power-driven vessel to other mariners.

The masthead light typically shines white and is positioned at least one meter above the deck, providing visibility over a significant distance from the front and sides of the vessel. This ensures that the vessel can be seen from far away, allowing other boats to avoid collisions, especially in low-light conditions such as at night or during periods of poor visibility.

Although the other types of lights—stern lights, combination lights, and anchor lights—serve important roles for specific scenarios, they do not fulfill the primary requirement for power-driven vessels. A stern light helps indicate the rear of the vessel, combination lights are a blend of different light functions typically used on smaller vessels, and anchor lights are used when a vessel is at anchor. However, the masthead light remains the standard requirement for operating a power-driven vessel on the water, ensuring that the vessel's presence and course are communicated to others effectively.