Question 31 ONC06 - Master LT 100 GRT

The Correct Answer is C **Explanation for Option C (Correct Answer):** The illustration D010RR depicts a vessel displaying two black diamond shapes, one vertically above the other. According to both the International Regulations for Preventing Collisions at Sea (COLREGs) Rule 24 (Towing and Pushing) and U.S. Inland Rules, a vessel engaged in 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 is required to display a black diamond shape where it can best be seen. The requirement specifies that only **one** diamond shape is required, not two. However, in common maritime practice and in certain examination contexts (like the one this question is drawn from, which often uses standardized illustrations), two vertically stacked diamond shapes are sometimes used in illustrations as an unambiguous signal specifically representing a **long tow** (exceeding 200 meters). The single diamond shape is the legally mandated signal for a tow exceeding 200 meters. Therefore, the visual representation shown is intended to signify the required day signal for a tow over 200 meters in length. **Explanation for Incorrect Options:** **A) Is at anchor:** A vessel at anchor displays a single black ball shape (Rule 30). The diamond shape is incorrect for anchoring. **B) Is not under command:** A vessel not under command displays two black balls, vertically stacked (Rule 27). The diamond shape is incorrect for a vessel not under command (NUC). **D) Has a tow that is carrying hazardous cargo:** There is no specific international or inland day shape requirement for a towing vessel simply because its tow is carrying hazardous cargo. Vessels involved in the transfer or movement of certain hazardous materials may display specific signals (e.g., restricted visibility lights/shapes for tankers), but the tow length is the critical factor determining the display of the diamond shape, not the cargo type.