Deviation is defined as the difference between which two headings?

Deviation is defined as the difference between which two headings?

• A. The difference between Magnetic Heading and Compass Heading
• B. The difference between True Heading and Magnetic Heading
• C. The difference between Ship's Course and Actual Path
• D. The difference between Bearing and Heading

Answer: (A)

Deviation is the angular error caused by the ship’s own magnetic influences, so it is the difference between what the compass shows and the direction toward magnetic north. In other words, it is the gap between Magnetic Heading (direction toward magnetic north) and Compass Heading (the reading on the ship’s compass). The amount and direction of deviation depend on the vessel’s iron, electrical systems, and other local magnetic effects, and it tells you how far the compass is off from the true magnetic reference. It helps to keep straight that variation is a separate concept: the difference between true north and magnetic north. Likewise, drift or track errors relate to the ship’s actual path versus its intended course, and bearing versus heading are about direction to a target versus the direction the bow is pointing.

Deviation is the angular error caused by the ship’s own magnetic influences, so it is the difference between what the compass shows and the direction toward magnetic north. In other words, it is the gap between Magnetic Heading (direction toward magnetic north) and Compass Heading (the reading on the ship’s compass). The amount and direction of deviation depend on the vessel’s iron, electrical systems, and other local magnetic effects, and it tells you how far the compass is off from the true magnetic reference.

It helps to keep straight that variation is a separate concept: the difference between true north and magnetic north. Likewise, drift or track errors relate to the ship’s actual path versus its intended course, and bearing versus heading are about direction to a target versus the direction the bow is pointing.