For fixed angle errors due to installation, the correction can be set in the following ways:
The actual course of the current ship must be determined by other means. If the display heading is larger than the actual heading, just dial the corresponding dial switch to make the display heading follow the number indicated by the switch (1 corresponds to 0.1 degree;...64 corresponds to 6.4 degrees) and decreases until the displayed course is consistent with the actual course. If the display heading is less than the actual heading, dial down the +/- switch and the corresponding dial switch until the display heading is consistent with the actual heading. After that, unless the GPS antenna is moved, the dial switch should never be moved at will.
