A thumb compass is a type of

compass A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with ...

commonly used in

orienteering Orienteering is a group of sports that require navigational skills using a map and compass to navigate from point to point in diverse and usually unfamiliar terrain whilst moving at speed. Participants are given a topographical map, usually a ...

, a sport in which map reading and terrain association are paramount. In cases of homogeneous terrain with few distinct features, a bearing between 2 known points on the map may be used. Consequently, most thumb compasses have minimal or no degree markings at all, and are normally used only to take bearings directly from a map, and to orient a map to magnetic north. Thumb compasses are also often transparent so that an orienteer can hold a map in the hand with the compass and see the map through the compass. Thumb compasses attach to one's

thumb The thumb is the first digit of the hand, next to the index finger. When a person is standing in the medical anatomical position (where the palm is facing to the front), the thumb is the outermost digit. The Medical Latin English noun for thumb ...

using a small

elastic Elastic is a word often used to describe or identify certain types of elastomer, elastic used in garments or stretchable fabrics. Elastic may also refer to: Alternative name * Rubber band, ring-shaped band of rubber used to hold objects togethe ...

band. The first commercially successful orienteering thumb compass was the Norcompass, introduced by Suunto in 1983. Placing an even greater emphasis on speed over accuracy, the wrist compass lacks even a baseplate, consisting solely of a needle capsule strapped to the carpometacarpal joint at the base of the thumb; the thumb serves the function of a baseplate when taking and sighting bearings. It is often used for city and park race

References

External links

Silva 6 Jet Spectra
a typical modern thumb compass
The Internet Compass Museum
gives comprehensive information about all sorts of compasses and how to use them. Orienteering Sports equipment {{Orienteering-stub

See also

References

External links