Compasses seem to come in all shapes, sizes and (especially) prices! What sets a good compass apart from a bad one and what are some good characteristics to look for when making a purchase?
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@MatBanik Up to a point, I'm more after the characteristics that make expensive compasses better and in what situations they're worth it over their cheaper counterparts.– berry120Jan 25, 2012 at 17:18
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4I don't know about anyone else, but I like my compass to point north.– Timothy StrimpleJan 25, 2012 at 17:21
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@MatBanik Advanced mainly - accuracy is important to me since a main use is letterboxing on Dartmoor where you need bearings at least to degree accuracy to triangulate your position properly.– berry120Jan 25, 2012 at 17:22
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Get one with a Romer scale if you need to plot grid references on a map– ChrisJan 25, 2012 at 17:24
2 Answers
As far as compasses are concerned I look for several things:
- Sealed liquid needle enclosure
- Creates a much easier to read measurement.
- Latching lid, to cover the needle and housing.
- Rotating bezel with Declination adjustment.
- Allows for offset of True North from Magnetic North, very important to accurate bearings as some regions in North America are up to 15 degrees off from true north
- Sighting notches in the case.
- Useful to sight a landmark, take a bearing, or for accurate triangulation of position.
- Glow in the dark degree measurements on the compass crown. (The ring around the body)
- A "Shed" for the bearing taking, this is a place where you put the needle when following bearings.
Additional nice to haves are:
- Long lanyard to attach to belt loop, and make knots for map distances.
- Sticky feet to grip a map during orientation.
- Various Standard, Imperial, and UTM (universal tranverse mercator) rules along the edge.
- Inclineometer.
- Bubble level.
- Mirror within case for signaling.
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1Also note that earth's magnetic field not only points north, but also, depending on where you are, slightly up or down. Get a compass that is made for the hemisphere (north/south) you intend it to use in, otherwise the needle might get stuck on the bottom/top of the compass Jan 25, 2012 at 22:27
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Good point about global compasses @Lagerbaer. Yes is is a best practice to have a global, not just North or South hemisphere compass. Jan 25, 2012 at 23:59
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You should look for the possibility to arrest the magnetic needle - that compass would be more resistant to failures.– TomasFeb 11, 2012 at 13:43
A high quality compass is shock resistant and sealed to a certain pressure level so that the needle always stays movable. Having a mirror which allows you to navigate while looking at your target or even moving can come in handy.
The vertical intensity of the magnetic field is not the same on the southern hemisphere as on the northern. This affects the needle's horizontal position. Some compasses come with exchangeable capsules. The pricier ones (mostly +50% of the price) do not require to change the capsule.