Question 34 GLI01 - Master-Unlimited Tonnage

The Correct Answer is A. A tugboat displaying the shape shown in illustration D010RR (a black diamond shape) signifies that the vessel is constrained by its tow and that **the length of the tow, measured from the stern of the towing vessel to the after end of the tow, exceeds 200 meters**. This signal is mandatory under both the International Regulations for Preventing Collisions at Sea (COLREGs Rule 24(a)) and the Inland Rules (33 CFR 89.25), which require a vessel or composite unit engaged in towing or pushing, when the length of the tow exceeds 200 meters, to exhibit a diamond shape where it can best be seen. **Why the other options are incorrect:** B) **Has a tow that is carrying hazardous cargo:** There is no specific shape signal in COLREGs or Inland Rules dedicated solely to indicating the presence of hazardous cargo on the tow. The diamond shape indicates the length of the tow. C) **Is at anchor:** A vessel at anchor displays one or two black ball shapes, depending on its length (Rule 30). The diamond shape indicates a long tow. D) **Is not under command:** A vessel not under command displays two black balls in a vertical line (Rule 27(a)). The diamond shape indicates a long tow.