🔍 Key Concepts

• Review Rule 25 – Sailing Vessels Underway and Vessels Under Oars in the Navigation Rules, especially the part about shapes when also using an engine. • Recall the day shapes for fishing vessels (cones, balls, diamonds) and how many shapes are used and in what combinations. • Pay attention to whether this symbol is one cone or a combination of shapes (e.g., cone + cone, cone + ball, etc.).

💭 Think About

• If a sailboat turns on its engine while still under sail, how is it classified under the Rules, and what day shape must it show? • Do fishing vessels under way show a single cone, or do they usually show a combination of shapes such as a cone with its apexes together or ball‑diamond‑ball? • Does the shape in the illustration give you any information about the tack (port/starboard) or the point of sail (close‑hauled), or do the Rules use different signals for that?

✅ Before You Answer

• Confirm in Rule 25(e) what shape is required for a sailing vessel also being propelled by machinery. • Verify that fishing vessels show a different arrangement of shapes than the single cone shown here. • Make sure you are not confusing tack or sailing angle (which has no day shape) with the required day shape for mode of propulsion.