Final answer:
Vessels restricted in their ability to manoeuvre and engaged in towing must display specific lights and shapes as defined by the COLREGs. This includes three all-around red lights and shapes when not making way, and additional white masthead lights when making way. Towing vessels also show a yellow towing light and additional masthead lights.
Step-by-step explanation:
The lights and shapes indicating a vessel restricted in its ability to manoeuvre, including those engaged in towing and not making way, are specifically defined in the International Regulations for Preventing Collisions at Sea (COLREGs). A vessel restricted in its ability to manoeuvre, when not making way through the water, must display:
- Three all-around red lights in a vertical line where they can best be seen.
- If it is practicable, three shapes in a vertical line where they can best be seen. The top and bottom shapes should be balls and the middle one a diamond.
- When making way through the water, in addition to the three red lights, they should also display white masthead lights, which show the direction the vessel is moving.
For a power-driven vessel engaged in towing and restricted in her ability to manoeuvre, the towing vessel must show:
- A yellow towing light above the stern light.
- Two masthead lights in a vertical line. If the tow is longer than 200 meters, three masthead lights in a vertical line are required.
These lighting configurations are critical for safety at sea as they convey to other vessels the operational status and limitations of the vessel, allowing for appropriate maneuvers to avoid collisions.