🔍 Key Concepts
• Vessel constrained by her draught – definition in International Rules (COLREGS)
• Day shapes for different vessel conditions (e.g., not under command, restricted in ability to maneuver, fishing, towing)
• Difference between International and Inland requirements for special shapes
💭 Think About
• First recall what it means for a vessel to be "constrained by her draught" and which types of vessels can claim this status
• Think through the standard day shapes: balls, cones, diamonds, cylinder – which ones are used for which conditions you already know (e.g., NUC, RAM, fishing, sailing under power)
• Ask yourself: is there a unique shape reserved only for a vessel constrained by her draught, and is it one shape or a combination of shapes?
✅ Before You Answer
• Verify in the International Rules (COLREGS) Annex I and Rule 3 that a vessel constrained by her draught has a specific day shape
• Confirm which shape is used for vessel restricted in ability to maneuver so you don’t confuse it with constrained by draught
• Make sure you are not mixing up shapes used for towing or fishing with the one for constrained by draught