🔍 Key Concepts

• Purpose of a magnetic compass binnacle on a vessel • How magnetic fields from nearby materials affect a compass • Difference between general durability (corrosion/weather) and magnetic influence

💭 Think About

• Which choice, if neglected, would MOST directly cause compass errors or unsafe navigation? • What property must the material have so it does NOT interfere with the earth’s magnetic field acting on the compass needle? • Think about why we use special metals and correctors around a compass—what are we trying to avoid or control?

✅ Before You Answer

• Identify which options relate only to physical durability (rust, rain, mounting) rather than compass accuracy. • Consider which property directly affects the magnetic environment of the compass. • Ask: if this property were missing, would the compass reading itself become unreliable, even if the binnacle stayed intact and watertight?