What is the difference between bearing and compass bearing?
In navigation bearing or course are given as either “true” or “compass” True is the bearing in relation to true north or the line on a map. Compass bearing requires compensation for the variation in the earths magnetic field, and any deviation in the compass itself. When plotting a course, to get compass bearing you start with the true bearing and or subtract variation to get magnetic bearing, then add or subtract and deviation to get the compass bearing. We learned the mnemonic TVMDC This has various expressions associated with it.
