Compass bezel watches
A compass bezel is one of those features that is more interesting than actually useful, though it does work. There are a few things to remember depending on your location and time of year.
To use it in the Northern Hemisphere, keep the dial level to the ground and point the hour hand towards the Sun. Then rotate the bezel so that the South marker points halfway between 12 and the current hour hand. Your cardinal points are now set.
If you're in the Southern Hemisphere, point the 12-hour indicator in the direction of the Sun. Then rotate the bezel until the North marker sits halfway between the hour hand and the 12-hour marker. This will set your cardinal points.
In both cases, the compass may not function properly at certain times of the year in low-latitude areas, as Seiko points out.
It's certainly a cool feature, at least for some of us, but if you really need reliable navigation, you could get a micro compass that attaches to your watch band.