"If the deviation figure exceeds 15° or the display shows no deviation value, the compass
is being affected by ferrous objects on your boat. You should move the compass
to a better location. Higher deviation figures are acceptable on steel
"Check the heading reading against a number of known headings, plot a deviation curve, and determine the heading alignment value that will give the lowest average alignment error. You can then enter this value on the Heading Alignment screen
, as described above. If the average heading error is more than 5°, you should perform the compass deviation correction procedure again, circling more slowly and in more favorable conditions."
Originally Posted by RedHerring
> DC wiring
anywhere near the sensor?
power wires live in the bilge
about a foot under under the sensor. No current
in them, of course.
Beware of intermittent interferences that can force a tack or a jibe.