1. What Is Compass Deviation?

Compass deviation is the error between magnetic heading and compass heading caused by local magnetic disturbances on a vessel or aircraft. It represents the angular difference between the direction indicated by a magnetic compass and the actual magnetic north direction.

2. How Does The Calculator Work?

The calculator uses the compass deviation formula:

Where:

• \( Magnetic\;Heading \) — The actual magnetic direction (degrees)
• \( Compass\;Heading \) — The direction shown by the compass (degrees)
• \( Deviation \) — The angular error between magnetic and compass headings (degrees)

Explanation: Positive deviation indicates easterly error (compass reads less than magnetic), negative deviation indicates westerly error (compass reads more than magnetic).

3. Importance Of Deviation Calculation

Details: Accurate deviation calculation is crucial for navigation safety, compass calibration, and ensuring precise course steering in marine and aviation applications.

4. Using The Calculator

Tips: Enter magnetic heading and compass heading in degrees (0-360). The calculator will compute the deviation and normalize it to the range of -180° to +180°.

5. Frequently Asked Questions (FAQ)

Q1: What causes compass deviation?
A: Deviation is caused by local magnetic fields from ferrous metals, electrical equipment, and other magnetic influences on the vessel or aircraft.

Q2: How often should deviation be checked?
A: Deviation should be checked regularly, especially after equipment changes, structural modifications, or when navigating in different magnetic environments.

Q3: What is the difference between deviation and variation?
A: Variation is the angular difference between true north and magnetic north, while deviation is the error between magnetic north and compass north due to local influences.

Q4: How can deviation be corrected?
A: Deviation can be minimized through compass swinging and adjustment using built-in corrector magnets on the compass.

Q5: What is a deviation table?
A: A deviation table shows the compass deviation for different headings, allowing navigators to apply corrections throughout the full 360° range.