There is at least one Model designed for the outdoors by Silva which has a built in compass. If memory serves me correctly one can deselect the GPS functions and just use the compass option. It is electronic, and will show the direction in which the top of the unit is pointing without the unit requiring any movement.
As for exactly how they work, I don't know.
The electronic compass is separate to the GPS receiver in the XL1000. THe receiver is actually made by Rockwell.
Last edited by compressor stall; 2nd Sep 2002 at 03:56.