What lights are exhibited by a vessel engaged in a towing operation that severely restricts its ability to deviate from its course?

A vessel engaged in a towing operation that severely restricts its ability to deviate from its course must display three all-round lights: an upper red light, a middle white light, and a lower red light. This configuration is specifically designed to signal to other vessels that the towing operation is significant, indicating the vessel's constrained ability to maneuver due to the tow. The upper red light signifies that the vessel is not only engaged in towing but also that it may have limited ability to alter its course, while the white light serves the dual purpose of showing it carries an operational aspect of navigation, and the lower red light further enhances visibility.

In addition to these lights, the vessel must exhibit the appropriate sidelights and sternlight commensurate with its size, ensuring it adheres to the conventions established under the International Regulations for Preventing Collisions at Sea (COLREGs). This lighting arrangement ensures that other vessels are adequately informed of the towing operation, promoting safety on the waters.