🔍 Key Concepts

• Magnetic compass construction – bowl, card, pivot, lubber’s line, and how they relate to the ship • Difference between compass heading and true north • Where the lubber’s line is physically placed in relation to the vessel, versus where the compass card is

💭 Think About

• Ask yourself: What piece of information do you personally use from a magnetic compass while steering a course? Is it something fixed to the ship or something that rotates? • Think about what moves when the ship’s heading changes: does the lubber’s line move with the vessel, or does the compass card move inside the bowl? • Which of the choices describe something that is always fixed in one direction (like north), and which describe something that changes as the ship turns?

✅ Before You Answer

• Verify whether lubber’s line is a mark on the ship/compass housing or part of the compass card itself • Check if the lubber’s line points to a constant direction (like true north) or to the direction the vessel is currently heading • Confirm whether the lubber’s line must be aligned with the vessel’s fore-and-aft line (centerline) rather than with the transom (stern)