🔍 Key Concepts

• Day shapes for vessels at anchor in the Navigation Rules (Annex I & related Rules) • Difference between shapes used for aground, constrained by draft, and not under command • Which single, simple shape is used most commonly to indicate a vessel’s status during the day

💭 Think About

• Think about what day shape you would see on a large ship sitting still at anchor just outside a harbor in good visibility. • Compare the shapes listed: which ones are normally used in pairs or in combination for special conditions (like sailing + power, fishing, or aground)? • Ask yourself: which of these is the basic, universal shape used alone to mark a vessel at anchor during daylight?

✅ Before You Answer

• Verify in the Navigation Rules – Day Shapes section which single shape is required for a vessel at anchor. • Check which shapes (cylinder, cone, double cone) are reserved for special conditions like constrained by draft or sailing with engine on. • Confirm that the shape for a vessel at anchor is a single, simple geometric shape shown in the forepart of the vessel.