Question 34 ONC04 - Mate of LT 500-1600 GRT

The Correct Answer is A. A tugboat displaying the shape shown in illustration D010RR (a black diamond shape) is indicating that its tow exceeds 200 meters in length. This is a requirement under the International Regulations for Preventing Collisions at Sea (COLREGS Rule 24), which mandates that a vessel engaged in towing, when the length of the tow (from the stern of the towing vessel to the after end of the tow) exceeds 200 meters, must exhibit a diamond shape where it can best be seen. This signal is used for both International and Inland waters (where COLREGS are applied or mirrored). **Why other options are incorrect:** **B) Has a tow that is carrying hazardous cargo:** There is no specific daytime shape prescribed by COLREGS (or general navigational rules) solely to indicate that a tow is carrying hazardous cargo. Vessels carrying dangerous goods follow specific marking requirements unrelated to the tow length diamond shape. **C) Is at anchor:** A vessel at anchor displays a black ball shape (or two balls if over 50 meters in length), not a black diamond. **D) Is not under command:** A vessel not under command displays two black balls in a vertical line, not a black diamond.