World Magnetic Zones

The horizontal and vertical components of the earth's magnetic field vary considerably at different locations. Most compasses are balanced for this magnetic inclination or dip by counterweights on the needle to prevent it from dragging on the top or bottom of the compass capsule. A compass needle that is balanced for use in North America will drag or stick in South America. For this reason Suunto balances compasses for 5 different zones. If the compass is used in an adjacent balancing zone, many compass pointers will tilt only slightly, however, the farther a compass is used from its correct zone, the more its pointer tilts. In extreme cases, the pointer will stick. For this reason it is extremely important to know in which zone a compass will be used.

Here is a simplified example of what happens to a compass balanced for Zone 1 when it is taken into the Southern Hemisphere.

Wide Screen Software LLC offers Zone 1 Compasses for the Northern Hemisphere. We often have TANDEMS for the other zones in stock. Please send us an email to inquire about the availability of Suunto TANDEMS for the other magnetic zones. [Availability Request]

Suunto has developed a patented global needle that will perform correctly in all 5 of the Earth's zones. This needle in used in Suunto's Global Navigator Compass.

Personal Observation:

I was able to use a Zone 1 TANDEM in Cozumel, Mexico, which is in the middle of Zone 2. The compass card (needle) had a definite tilt but was within the tolerances of the TANDEM. By slightly tilting the instrument I was able to make accurate readings. I feel that you will be able to use the TANDEM, KB-14 and VISTA compasses in an adjacent zone, but beyond that you should follow Suunto's recommendations.