If a tug is towing three barges and is overtaken by a vessel under sail from dead astern, which vessel must give way?

In this scenario, the correct choice is that the tug must give way. According to the International Regulations for Preventing Collisions at Sea (COLREGs), when a sailing vessel is overtaking, it has the right of way. This applies specifically to a vessel that is under sail, indicating it is not mechanically propelled, which is relevant in maritime navigation rules.

When a tug is towing multiple barges, the entire tow is treated as a single entity for navigation purposes. The tug, as the vessel that is not under sail, is considered to be a power-driven vessel. So, when it is overtaken by a vessel under sail from dead astern, the power-driven vessel (the tug in this case) is required to give way. This is true regardless of the tug's status as it is towing, emphasizing the importance of navigation rules prioritizing vessels that are not able to maneuver as easily as others.

Understanding this scenario helps navigate the complexities of maritime rules, especially when determining right-of-way situations involving vessels with different means of propulsion.