Which light configuration indicates a sailing vessel that is under power?

A sailing vessel under power is required to display a light configuration that is the same as that of a power-driven vessel. This means that when a sailing vessel is using its engine, it must show a masthead light (white light positioned at the top of the mast), sidelights (green on the starboard side and red on the port side), and a stern light (white light at the back). This configuration clearly indicates that the vessel is operating as a power-driven vessel rather than solely under sail.

The other configurations mentioned do not accurately represent a sailing vessel that is under power. For instance, only displaying anchor lights would suggest that the vessel is at anchor and not underway. Sidelights alone would not be sufficient to indicate that the vessel is under power, as these lights need to be complemented by the masthead and stern lights for clarity in navigation. Flashing lights are typically reserved for specific types of vessels or signaling situations, but they do not represent a standard configuration for a sailing vessel under power. Thus, the light configuration for a sailing vessel under power must comply with the same requirements as that of a power-driven vessel.