True north and magnetic north are not the same. The difference between them is called:

• A. Deflection
• B. Variation
• C. Deviation
• D. Offset

Answer: (A)

The difference between true north and magnetic north is the angular separation caused by Earth’s magnetic field. Navigators need to know this angle to convert between map directions (true north) and compass readings (magnetic north). In this context, that angle is called deflection. It tells you how far the magnetic north line is from true north, so you can adjust bearings accordingly. For example, if true north is 0° and magnetic north is 10° east, the deflection is 10° east, and you would apply that to align your compass with the map. The other terms refer to related ideas: variation/declination is the general term for the difference between true and magnetic north, deviation is the error caused by local magnetic interference in a vessel, and offset isn’t used here.