COLREGs Lights & Shapes Practice Test - Prep & Study Guide

A towing vessel engaged in a towing operation necessitates three all-round lights in a vertical configuration, which provides clear visibility and identification of the vessel's operational status to other mariners.

The top light indicates that the vessel is engaged in towing and is thus larger and potentially more hazardous than a simple power-driven vessel. The middle light, as part of the three-light arrangement, signifies that the vessel is towing another vessel or any object, while the lower light serves to highlight the stern of the towing vessel itself.

This specific configuration is crucial for safe navigation, as it informs other vessels about the nature of the towing operation, including the length and ability to maneuver of the vessels involved. Understanding this light configuration aids other ships in maintaining safe distances and adhering to maritime navigation rules, reducing the risk of collisions.