Compass Tips

Posted: 12/23/2014 in Land Navigation

Some compass use tips and techniques:

Hold the compass level when taking readings. If you tilt the compass, you risk burying the needle and getting a false reading. I teach new students two methods to hold the compass. At http://www.maxvelocitytactical.com/2014/12/land-navigation/ , he points to this site:  http://armyguru.com/training/navigation . Select “compass”, to see both methods.

Method 1:  My method is a modified version of the method in the picture. Hold the compass in both hands, palms up, one palm resting over the other, with both thumbs pointing forward along each respective side of the compass. Hold it at waist level locking your elbows into your sides. Face your objective square-on, then look straight down at the level compass to get your azimuth (heading) to the objective. Do not only turn your hands to face your objective but instead turn your entire body to face it. When you feel comfortable with this method, raise the compass to chest level, still holding the compass the same with elbows locked in to your sides and then glance down to get your azimuth. After some practice, you should be able take periodic compass reading while holding the compass in one hand while walking. It is a good idea to periodically switch hands when using the dead-reckoning method of navigation. This will help correct drifting to one side or the other.

Method 2:  To get a more precise reading you can fold the hinged, mirrored top of the compass over the base at approximately 45 degrees, hold the compass to your cheek and use the sighting aperture and sighting wire to line up your objective while reading the azimuth in the mirror. If you’re wondering why you would want a precise measurement, remember, most good compasses are graduated every 2 degrees on the bezel. Keeping this in mind, scroll down to DTGs great article on magnetic declination (below) and look at the error-rate-per-meter. While land nav. is not surveying, it might be a good thing to be able to correctly triangulate your current location using several distant mountain peaks.

Some general use tips:

Keep your compass away from all ferrous metals when taking a reading. Items include:  metal framed glasses, rings, watches, bracelets, belt buckles and gear with metal buckles/snaps, sidearms and long guns, old style steel-pot helmets etc. Concrete structures that are filled with re-bar/wire mesh to include slabs, over septic tanks etc. Metal buildings, buried electric power and telephone cable, buried or above ground concrete and metal pipes, wooden picnic tables that are nailed together and last but not least – in/around vehicles to include vehicle hoods that your new 2nd Lieutenant just spread the map out on (Come on L.T., WTF over?). You get the picture.

Again, protect your compass. Attach it to your person, close it up and put it in your pocket/pouch when not using it.

Ensure you are pointing the compass at your objective with the direction of travel arrow away from you (Come on L.T., WTF over?).

Trust your equipment. Before you start to second guess your compass, take out your backup compass (two is one and one is none) and compare readings. Don’t hold the compasses against each other, they will give false readings. The more you train with it, the more you will trust it.

Up next:  Dead Reckoning vs. Terrain Association

DOL

DM

 

 

 

 

 

 

 

 

 

 

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Comments
  1. Hopefully, folks new to land nav and using the USGI lensatic compass users won’t think theirs works the same as the MC2 for sighting. The USGI lensatic compass cover should be at 90 degrees to the base for sighting, with the eye piece at an approximate 45 degree angle, and ensure the dial spins freely. Otherwise, you won’t sight accurately.

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