Map and Compass Basics: Magnetic Declination

Understanding and setting declination on your baseplate compass

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• map and compass
• magnetic declination

[stewart00311]

What Brand of compass is that?

[safariskills]

@stewart00311 A Sylva Polaris (~ $12). 

[Boricuaso77789]

Can't we get a better accuracy using a handheld gps

[safariskills]

A handheld GPS is a great tool for pinpointing location. It is not as good as a compass for accurately determining direction, especially while standing still. A GPS has some other drawbacks--weight, price, reliance on a clear view of the sky, batteries, etc., so map and compass skills (at least as a backup to GPS) are still important for outdoor recreation.

[MrRocque]

@Boricuaso77789 only if your gps has many fixes (horizon satellites are the most accurate but hardest to lock onto) and you have batteries that work, you're in the middle of a barren field with clear skies and no interference. Even then, the accuracy can be as bad as 25 ft (in any direction, ie. 50 ft). With a USGS 1:24,000 map of the area, one can determine their location to with 10 ft. Each 'system' has its pros and cons but a person should know how to use map/compass before relying on tech.

[safariskills]

@MrRocque Yup, all good points. Another potential problem to add to the list is choosing the wrong map datum when using GPS coordinates with a map. I have seen > 150 meter errors. There are GPS units and techniques that can produce sub-meter (or even sub-centimeter) accuracy, but these are often impractical and/or too expensive for recreational land navigation.

[Undeworld667]

Lol sinister music :D

[dandrader]

Finally found a place that actually explains how to adjust the declination in an adjustable compass (the little screw). Now it all makes sense! :)

[stewart00311]

Thanks for the info.

Good entry level training

[Boricuaso77789]

Thanks for the help

[benedicts11]

Thanks for this post. Very informative.