Question 645Navigation General

The correct answer is B) compass error. The standard magnetic compass heading differs from the true heading due to compass error, which is the combination of variation (the angle between true north and magnetic north) and deviation (the magnetic interference caused by the ship's iron and steel components). Variation is a geographic phenomenon that affects all compasses in a given area, while deviation is specific to the individual vessel. The other options are incorrect because: A) Variation is a component of compass error, but not the entire difference. C) Deviation is a component of compass error, but not the entire difference. D) Latitude does not directly cause the difference between magnetic and true heading.