Magnetic forces contained within your kayak can cause your compass to read an incorrect bearing. This type of error is known as magnetic deviation. With 1 degree of compass error, over a mile, you’ll end up about 92 feet away from your destination. 1 degree of compass error equals 92 feet per mile of ground error. If your deviation is extreme like shown in the image, you could completely miss your target by over 1.7 miles on a 10 mile crossing. Worse still, deviation varies as you turn your kayak. For example, you might have a negative 10 degree error when pointing northwest, but that might change to a positive…