Why should I calibrate the compass? How do I calibrate the compass?
Any time the Cobalt is moved a significant distance on the earth- and by that we mean hundreds or thousands of miles, not just a few- the compass calibration should be redone. Instructions are on Page 8 of the Cobalt manual, which can be downloaded here.
How well the compass performs is very much dependent on calibration accuracy- even a couple of degrees off from a true 180° rotation or a 180° flip to upside-down will have an effect, so doing it very carefully is important. If you do not have the original box, as shown in the instructions, fastening the Cobalt inside a small rectangular box can help the calibration be more accurate. It is possible to do the calibration freehand, but since the Cobalt case does not provide straight surfaces it is necessary to be very careful to rotate as close to 180° as possible.
Problems with Compass Calibration: Most calibration problems are caused by being too close to ferrous metals. Ferrous metals can be hidden in table tops, metal supports, reinforcements in concrete surfaces, or nearby electric motors. If you experience problems with calibration vary the spot where you do the calibration.
In very rare instances, environmental conditions (mainly exposure to strong magnetic fields) might possibly require the underlying initial factory calibration to be redone. This is a service procedure that can be carried out by a qualified dealer, or by Atomic Aquatics. If careful calibration attempts fail, contact your Atomic Aquatics dealer.