🔍 Key Concepts

• Day shapes for vessels under special conditions in the Navigation Rules (Part C - Lights and Shapes) • Difference between vessel not under command, vessel restricted in her ability to maneuver, and vessel constrained by her draft • How minesweeping vessels are marked by day shapes

💭 Think About

• For each vessel type in the choices, picture (or sketch) the required day shapes and count how many there are and how they are arranged. • Ask yourself: which condition describes a vessel that has limited ability to move or change course because of the work it is doing, not because it has lost all power or control? • Think about which of these categories is associated with the distinctive ball–diamond–ball pattern in the Rules.

✅ Before You Answer

• Verify in the Navigation Rules which vessel shows ball–diamond–ball shapes in a vertical line. • Confirm how many shapes a vessel not under command shows and what they are. • Check that a vessel constrained by her draft does NOT use a ball–diamond–ball pattern, and note what single shape it does show.