🔍 Key Concepts

• Navigation Rules, Annex I and shapes in Part C – Lights and Shapes • Meaning of a single black ball day shape versus shapes used for towing or fishing (cone, diamond, ball–diamond–ball) • Rule 30 (Anchored and aground vessels) compared with Rule 24 (Towing) and Rule 26 (Fishing)

💭 Think About

• First, identify how many shapes are being shown and whether they are balls, cones, or diamonds. What does one black ball on its own represent? • Compare the illustrated shape to what is carried by a vessel that is towing or fishing—do those usually show just a single ball, or combinations like cone/diamond/ball-diamond-ball? • Ask yourself: which of the options would most logically be associated with a simple, single warning shape that other vessels commonly see in harbors and anchorages during the day?

✅ Before You Answer

• Verify in the Navigation Rules that towing vessels show special shapes only when the tow is long, and note what those shapes look like. • Check Rule 26 to see that fishing vessels display shapes involving two cones with apexes together (or other combinations), not just a single ball. • Confirm under Rule 30 what day shape a vessel must show when not making way through the water but still required to be seen and avoided.