When towing, what lights must a power-driven vessel exhibit?

The correct choice requires an understanding of the navigation lights that power-driven vessels are mandated to display when towing. A power-driven vessel engaged in towing must exhibit two masthead lights arranged in a vertical alignment as a standard. This configuration not only aids in identifying the vessel's status but enhances visibility for other vessels in the vicinity.

Furthermore, if the length of the tow exceeds 200 meters, an additional masthead light is required, bringing the total to three masthead lights. This requirement is crucial for alerting other vessels to the size and status of the towing vessel, thereby promoting safety and reducing the risk of collisions.

The setup of these lights allows mariners to assess the towing situation accurately from a distance, assisting with nautical navigation and ensuring compliance with maritime regulations.