What configuration must a power-driven vessel pushing ahead or towing alongside exhibit on the Western Rivers?

The correct configuration for a power-driven vessel pushing ahead or towing alongside on the Western Rivers is to exhibit sidelights and two towing lights. This is in accordance with the specific navigation light requirements for vessels engaged in towing operations, particularly in restricted visibility situations.

When a power-driven vessel is conducting towing operations, the presence of two towing lights (one above the other) enhances the visibility of the vessel's intentions and actions to other mariners. These lights are typically positioned on the stern of the towing vessel and indicate the operation taking place. The sidelights are also required to provide general navigational visibility, allowing other vessels to determine the course and heading of the towing vessel.

This combination of lights ensures that the vessel is correctly signaling its operation, which is crucial for maintaining safety on the waterways. It clarifies the size and arrangement of the vessel and the towing situation, helping to prevent collisions. The specific requirements for different configurations of towing operations are outlined in the International Regulations for Preventing Collisions at Sea (COLREGs), as well as additional regulatory guidance specific to waterways like the Western Rivers.