Which vessels display two towing lights in vertical alignment?

Power-driven vessels on the Great Lakes display two towing lights in vertical alignment when they are towing another vessel. According to the COLREGs, these vessels are required to show these lights to indicate their status and the nature of their operation, particularly when they are engaged in a towing activity.

The two towing lights must be positioned one above the other to clearly signal to other vessels that they are performing a towing operation. This configuration is specifically relevant in navigable waters like the Great Lakes, where certain maritime rules are adapted to account for local conditions and traffic patterns. The two vertically aligned towing lights enhance visibility and help prevent collisions by effectively communicating the vessel’s activity.

Other options do not pertain to this specific lighting requirement. Fishing vessels in restricted visibility would showcase lights appropriate for fishing activities, not towing. State vessels engaged in law enforcement typically have a different array of lights indicating their operational status. Sailing vessels under power would indicate their status using standard lights for sailing vessels, not specifically towing lights.