 It then gives for every different quarter wind of sailing direction (always designated as quarters away from the north-south axis, rather than away from the intended course), the "relevar" and the "afastar".The "relevar" is the number of leagues on the actual course that a ship must sail in order to cover the pre-set 1 degree of latitude (17.5 leagues of "alargar" from the starting parallel).The "afastar" is merely the corresponding "avanzar" on the west-east bearing.