Monday, August 25, 2014

Wilderness Survival: Use the North Star to set your compass declination to True North

Compasses are indispensable tools for wilderness navigation. Problem is, they point to Magnetic North instead of True North. Why is True North important? Consider this-- Magnetic North was located near Ellesmere Island in northern Canada in 2005. In 2009, it was still situated within the Canadian Arctic territorial claim, but it was moving toward Russia at between 34 and 37 miles (55 and 60 km) per year.

By contrast, True North is where the North Pole is located, and does not change. As you can see, using Magnetic North for your bearings could result in less than accurate navigation in the wilderness, especially as it relates to using a map.

"Declination" is the difference in degrees between these two poles. Setting the declination on your compass's bezel is what allows it to point to True North instead of Magnetic North. Declination varies from region to region, and the exact setting is usually obtained from a topo map, local USGS Office, or via the NOAA site online.

So what do you if you're lost and don't know the declination of your area, or the map you had with the local declination setting got lost on the trail? No worries, just use the North Star (Polaris) to set your declination.

The North Star is always positioned over the North Pole in the night sky, so it can be used to adjust your compass's declination to True North.

Simply find the North Star as shown in the main photo above, point your compass at it, and set your compass's bezel to a bearing of 0 Degrees. This will then set your compass's declination to True North, giving you more accurate navigation in the backcountry.

NOTE: Contrary to popular belief, the North Star is not the brightest star in the night sky. In fact, it can be quite dim compared to many other stars. It is important to find it by memorizing its position in relation to the constellations instead of looking for a bright, prominent star.

High Altitude NOTE: At high altitude, you will need to use a crude Plumb Bob (rock tied to a string) to get a more precise alignment with your compass and the North Star in order to set your Declination. For more information on how to do this, check out Rescue Dynamics's detailed writeup about dealing with Magnetic Declination in the backcountry.

About the author
Jason Schwartz is the founder and senior editor of Rocky Mountain Bushcraft. He is a former Red Cross certified Wilderness & Remote First Aid Instructor, and has taught bushcraft and wilderness survival techniques to the Boy Scouts of America, interned with the US Forest Service, and studied wilderness survival, forestry and wildland firefighting at Colorado Mountain College in Leadville, Colorado. Jason has also written for magazines such as The New Pioneer and Backpacker, including writing the "Tinder Finder" portion of Backpacker's "Complete Guide to Fire," which won a 2015 National Magazine Award (NMA). Email him at rockymountainbushcraft @ (without spaces)

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