Within a narrow channel, what color lights must a tugboat pushing?

A tugboat pushing a vessel in a narrow channel is required to display the same color lights as a power-driven vessel. According to the Navigation Rules, a power-driven vessel that is under way at night must show a white masthead light and sidelights: red on the port side and green on the starboard side.

When a tugboat is pushing, it is considered to be operating as a power-driven vessel, which is why it follows the same lighting requirements. This ensures that other vessels in the vicinity can easily recognize its status and navigate safely around it, thereby minimizing the risk of collisions in the often constrained space of a narrow channel.

Moreover, this alignment with the lighting requirements of power-driven vessels fosters a clear understanding among mariners about the type of vessels they are encountering, which is fundamental for maintaining safety and order in maritime traffic.