Compass direction using a watch: Difference between revisions

Revision as of 10:55, 24 April 2008

Revision as of 22:42, 25 April 2008

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== Using a standard watch ==

Using a standard 12-hour watch, such as a wristwatch, one's approximate bearings on the norther hemisphere can be found as follows:

# HoldRotate the watch withsuch 12that o'clockthe hour hand is pointing towards yourthe leftSun.

# RotateThe intopoint positionhalfway so thatbetween the hour hand isand 12 o'clock then pointingpoints towards the Sunsouth.

# The point halfway between the hour hand and 12 o'clock points towards the south.

There are minor inaccuracies due to the difference between [[local time]] and zone time, and due to the [[equation of time]].

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During [[daylight saving time]], the same method can be employed using 11 o'clock instead of 12.

On the southern hemisphere, the same holds for the northern direction.

[[Image:Direction_Watch.jpg|thumb|220px|left|Specialized 24-hour watch with compass card dial]]

==Explanation==

On the northern hemisphere, at noon, the sun appears in the southward direction. The sun performs its circle in 24 hours, thus with half the speed of a 12-hour watch's hour hand. Therefore the angle has to be bisected.

== Direction-finding watch ==

[[Image:Direction_Watch.jpg|thumb|220px|left|Specialized 24-hour watch with compass card dial]]

The photograph to the left shows a specialized 24-hour watch optimized for finding directions using the Sun. With the watch set to indicate local time, the hour hand points directly at the Sun. North is indicated by the local noon position (in the Northern Hemisphere).