NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bruce J. Pennino
Date: 2012 Nov 5, 17:55 -0500
----- Original Message -----From: Bruce PenninoTo: NavList@fer3.comSent: Monday, November 05, 2012 11:39 AMSubject: [NavList] Re: Accuracy of backpacking compassHello:Out of curiosity I gathered the 4 compasses I have laying around the house and my field surveying kit. All of my compasses are low cost.....some might cheap.All four compasses pointed mag north , a good starting point, and did not vary by more than a degree or two. When aimed mag south, one compass did not hardly move without shaking it. The needle dragged so badly it was useless. My experience is that students must be reminded that the compass must be held level and wobble it a little to be sure that there is free movement of the needle.Two basic Suunto plastic "lay on a chart" type compasses were off by 10 degrees or more on mag south. My Army style compass with a folding cover and wire, plus a magnifying glass on the glass was accurate to within 3-4 degrees on mag south. I was quite surprised, especially knowing how this compass has been abused for decades!I say the very best you can do is plus or minus a few degrees with a quality Brunton, Suunto or similar type compass. Because the scales are so small, magnification is important and a sighting wire or view finder are important. For ordinary circumstances, hand held plus or minus 5 degrees is probably a typical accuracy and plus or 7 or 8 is readily achievable.
Bruce----- Original Message -----From: Gary HublerTo: NavList@fer3.comSent: Monday, November 05, 2012 11:03 AMSubject: [NavList] Re: Accuracy of backpacking compassI use the U.S. Army 'Lensatic Compass' made by Cammenga for backpacking. It is a compact compass that is great for taking azimuths. The Army teaches their young officers land navigation using this compass. It has a luminous bezel indicator, induction damping for fast azimuth acquisition, and a sighting system to get more accurate readings.
The key with this type of compass is that you need to learn how to use it properly. Proper instructional material is available on the web at no cost.
There are some cheap knock-offs on the market, so if you like this type of compass, be sure to get the one made by Cammenga.
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