Deviationstabel & -kurve

Deviation is a term for the deviation a compass exhibits due to magnetic influence from iron parts in the vicinity of the compass. For example on board a ship. Deviation is measured in degrees relative to the direction in which the compass needle would point if the compass were located somewhere without this local magnetic influence. If you want to sail a certain course according to the compass, you will have to correct for the deviation. If the deviation is, for example, 12 degrees, you must sail a course where the compass needle points 12 degrees higher than the actual desired course. The deviation is different from ship to ship, as it is determined by local conditions. The deviation will also be different depending on which course the ship is sailing. The deviation can be, for example, 12 degrees when sailing to the southeast and 7 degrees when sailing to the north. In order to keep track of this, a so-called deviation table is prepared for the vessel in question. In the deviation table, you can see the concrete deviation based on the specifically sailed course, and thus how much you have to correct the course shown by the compass.