SILVA COMPASSES		RECTA COMPASSES		BUDGET COMPASSES

The compass is believed to have its origin many centuries ago in China when it was discovered that a free or floating magnetic (compass) needle always pointed in the same direction....magnetic north, a point on the earths surface, not fixed, but slowly and erratically migrating in the north polar region. The compass needle floating in the earths magnetic field, always points to magnetic north which in reality is close to true north but sufficiently different to make a small adjustment necessary for accurate navigation. This is known as magnetic variation or declination. Most maps have their own north known as grid north and to accurately use the compass and navigate safely these relationships should to be understood. Good maps will provide the necessary figures in their information as it differs for each location.

Most compasses are balanced to operate at specific latitudes as the magnetism acting on the needle causes it to dip towards the poles. Normally this inclination does not impair performance wherever you are but some of the more expensive compasses compensate for this problem. Deviation is an error in a compass reading caused by local conditions interfering with the magnetic force acting on the compass needle, such as metal objects, radios, mobiles, tins and even rings and watches. Care should be taken to achieve the best accuracy.

for Silva compasses and recta compasses see above