Question 34 OSV02 - Mate - Offshore Supply Vessels

The Correct Answer is A. A tugboat displaying the shape shown in illustration D010RR is displaying a black diamond shape. This signal is prescribed by the International Regulations for Preventing Collisions at Sea (COLREGs), Rule 24 (Towing and Pushing). Rule 24(a)(i) states that a power-driven vessel when towing and the length of the tow (measured from the stern of the towing vessel to the after end of the tow) exceeds 200 meters shall exhibit, in addition to standard lights, **a diamond shape where it can best be seen**. Therefore, the tugboat has a tow that exceeds 200 meters in length. **Why the other options are incorrect:** * **B) Has a tow that is carrying hazardous cargo:** There is no specific day signal (shape) under COLREGs or Inland Rules mandated for a vessel towing hazardous cargo. While special signals or marks might be required in certain ports or waterways, the black diamond specifically denotes the length of the tow, not the nature of the cargo. * **C) Is at anchor:** A vessel at anchor exhibits a black ball shape (Rule 30), not a black diamond. * **D) Is not under command:** A vessel not under command exhibits two black balls in a vertical line (Rule 27(a)), not a black diamond.