🔍 Key Concepts

• Magnetic compass components and what each does • How a ship’s actual heading is read on a compass • The purpose and location of the lubber’s line on a binnacle compass

💭 Think About

• On a standard ship’s magnetic compass, which part actually moves and which part stays fixed to the ship? • When you call out the vessel’s heading to the helm, what exactly are you reading: a moving pointer, fixed line, or the rotating scale? • Which component is physically aligned with the vessel’s fore-and-aft line (bow to stern)?

✅ Before You Answer

• Identify which part of the compass is fixed to the ship’s structure rather than rotating freely. • Confirm which part is aligned with the keel/centerline of the vessel. • Make sure you are choosing the part that indicates the heading rather than the part that senses Earth’s magnetic field.