🔍 Key Concepts
• Rule 24 (Towing and Pushing) – International Rules: day shapes and lights for towing and for inconspicuous partially submerged tows
• Which day shape is used to mark the extremities of very long tows (forward and aft ends) when the tow’s length exceeds certain limits
• Recognizing standard day shapes: ball, diamond, two cones apex together, single cone and what each normally indicates (e.g., restricted ability to maneuver, sailing with machinery on, etc.)
💭 Think About
• Look at Rule 24 for an inconspicuous partially submerged object: when its length exceeds 100 m, what extra day shape must be added toward the forward end, in addition to the one already required at the after end?
• Among the four illustrated shapes, which one is specifically associated with ‘long tow’ extremities rather than with a vessel constrained by draught, restricted in ability to maneuver, or a power-driven sailing vessel?
• Ask yourself: if you saw this shape displayed on a long tow in daylight, what would it immediately tell other vessels about the tow’s overall length and hazard? Which of the options fits that role in the Rules?
✅ Before You Answer
• Verify in Rule 24(g) that an inconspicuous partially submerged tow over 100 m must show a specific day shape at or near each end (and at intervals not exceeding 100 m if very long).
• Match that required shape from the Rule’s text to the exact silhouette shown in options A–D; be sure you know which picture is the ball, which is the diamond, which is two cones apex together, and which is a single cone.
• Confirm that the chosen shape is not the one used for a vessel constrained by draught or for a sailing vessel also under power; eliminate those before picking your answer.