Points of the compass Points of the compass The points of the compass mark the divisions on a compass, which is primarily divided into the four cardinal directions: north, south, east, and west. These points are further subdivided by the addition of the four intercardinal (or ordinal) directions—northeast (NE), southeast (SE), southwest (SW), and northwest (NW)—to indicate the eight principal winds. In meteorological usage, further intermediate points between the cardinal and intercardinal directions, such as north-northeast (NNE) are added to give the sixteen points of a compass rose. At the most complete division are the full thirty-two points of the mariner's compass, which adds
Compass points on the shore. A compass deviation card is prepared so that the navigator can convert between compass and magnetic headings. The compass can be corrected in three ways. First the lubber line can be adjusted so that it is aligned with the direction in which the ship travels, then the effects of permanent magnets can be corrected for by small magnets fitted within the case of the compass. The effect of ferromagnetic materials in the compass's environment can be corrected by two iron balls mounted on either side of the compass binnacle. The coefficient formula_1 representing the error in