141

The reason is that you could miss your destination and hit a trail and know that you are almost there, but not know which way to turn. So if you were to go straight for the destination, and because of Murphy or errors or whatever and you ended up at either Point A or Point B, you wouldn't be certain of which way to turn to reach the trail intersection. If ...


127

In addition to the case described by Charlie (and to show that I also can make drawings in Paint), there is the case where you want a stopping line to know when you are going too far. This is mainly useful when you are aiming for the end of a feature. The drawing below is with a river bend that you try to reach, but the same principle works when aiming for ...


18

Prerequisites: A Topographical Map for the area you are in. Ordnance Survey's Landranger series cover all of the UK. A compass suitable for the task. (I use the Silva Expedition 54) Knowledge of your current location on the map. Step 1: Taking Bearing. Point your compass at the distant peak. (This is done without a map, by physically looking at the ...


13

I wouldn't call it normal, but it does happen and if the bubble is large enough it will effect your accuracy. In that case you may want to purchase a new one or if possible send it back to the manufacturer. From Silva's FAQ page We intend that our compasses are free of bubbles; however, if a small bubble forms in the liquid-filled capsule, it has no ...


13

I was in the Army Infantry in the '90s when we still used maps and compasses to get through the woods. People have a tendency to veer off to the side of the hand holding the compass when they are land navigating, especially at night. You could try to compensate by switching which hand you are holding the compass with periodically during that leg of the ...


11

Source: John Baldwin: Slope Angles from Map Contours View this page for a refresher on how to do the maths to calculate slope on a topographic map.


11

Yes, there are certainly areas where there magnetic anomalies. There is on in the Kursk area of Russia that is caused by a very large iron deposits. There is also one in Africa that they are not certain of the cause, but the effect on a person's compass is described as, “If you were on the ground there and you had a magnetic compass, you’d need to correct ...


10

A catch feature is a feature that you will run into, if you have gone too far. As you can see above, if you are using the stream as a handrail feature to get to the bridge in order to cross, the trail acts as a catch feature. If you are heading towards a catch feature and not following a handrail, then you will want to aim off. Some examples of things ...


10

A handrail feature is something that you can travel paralleled to in order to reach your destination. A good example of this would be a stream/river as while you wouldn't want to follow directly beside it due to any swamps/marshes/beaver dams or trying to follow the bends, staying parallel to it, would help prevent you from getting lost. A few other ...


10

Contouring means to follow the contours of the land to your destination, trying to stay at the same elevation as you work your way around the hill. In this example you would walk up the hill, and upon reaching the given height, stay at that level while walking towards the destination. Sometimes, in places without trails, you will know the elevation of your ...


9

The steps are rather simple for following a bearing without always looking at your compass, Pick a distant recognizable point (stump, rocks, tree) on your bearing. Travel to that point (not necessarily in a straight line). Pull out your compass and repeat. The reason for picking out the distant point is that you can run to it and not have to look at your ...


8

The basic idea behind triangulation is take multiple bearings with the compass to recognizable points and draw them on the map. Where they intersect is your location. You want the lines to be as close to perpendicular as possible, for the sake of accuracy. The reason is that when the lines are perpendicular, a change in the angle isn't as significant. ...


7

I don't believe such an easy method exists you can keep in your head and calculate. The position of the moon relative to you depends on accurate knowledge of the phase of the moon, time of day, and latitude and longitude of where you are, and those interact in a nonlinear manner. Your original claim isn't even true in all places. The moons rotation is ...


7

Navigation - be it either over land or sea - is governed by non-Euclidean geometry, which means dealing with a sphere instead of a plane. This also means that shortest path between two points on a sphere will never be straight line (unless you can dig really fast). This shortest route is called orthodrome. When bearing is designated by compass only we pass ...


6

They certainly can and it is caused by, Please be aware that a reverse polarity is caused by exposing your compass to articles with iron content (something as simple as being placed next to a pair of scissors or a knife for a length of time, microwaves, high tension wires, etc.). Source Magnetic fields exist around many items we commonly carry with us ...


6

I have observed the same thing with compasses as well as level gauges. I'd say that it's normal unless it is hampering the accuracy beyond an acceptable degree of error. That regular small bubble is left in order to prevent the outer casing from breaking when the liquid expands when it gets heated. Liquids are not compressible, so that air bubble which is ...


6

What you mean is called "Orientierungslauf" or in short "OL" in Germany. There are some events, but it is best you get in touch with some organizers over there perhaps using this list of upcoming orienteering marches. In my experience the events of this kind which are not highly popular are mostly not (yet) present on the internet. It's "popular" around ...


5

Sometimes landmarks that you are travelling from, are much easier to take bearings to than what you are travelling towards. For example, in southern Utah near Bryce Canyon, there is a cinder cone that rises several hundred vertical feet above a relatively flat forest. Taking a bearing to the cinder cone is easy since it rises well above the forest. ...


5

To put it really simply, an attack point is something that you can aim towards, that is far more obvious and easy to navigate to than your actual destination. For examples consider navigating to a lava tube cave in a forest with bluffs around. While the cave won't be visible until you are really close to it, the bluffs will stick out above the trees and you ...


4

The OP provides an nicely detailed self answer, but I would like to add that when such areas exist, they are of particular concern to mariners1, and are therefore well-documented for nautical navigation purposes. I will use as my example an area at the north-eastern end of Lake Ontario, as it begins to meet the St. Lawrence River. The anomaly lies in the ...


3

The answer is really dependent on language, I think. Being from a French-speaking part of the world, I can definitely say that even in orienteering/mountain traveling, the meaning of contouring would imply simply going around a feature, not necessarily at a fixed elevation. I could contour around a forest or a hill. The translation of contourner is quite ...


2

Another trick you can use if it's sunny and open enough for shadows: Take a bearing, and note the angle of the shadows to your bearing, or to the sun to your bearing. You still need to check this now and then, but it can help maintain a course when all distant landmarks look alike. I don't generally use a compass much orienteering. I use my map more, '...


2

There's a German organization. Their website can be found here. It's best for you to ask them for further information. You can contact one of these people.


2

You need to know whether the magnetic declination you have was measured from Grid North or from True North. If you have a Grid declination, then you align the north arrow of the compass with Grid North (the frame of the map) before adjusting for declination. If you have a True declination, then you align the north arrow of the compass with True North (the ...


2

The problem you describe is known in surveying as three point resection – essentially you need to observe angles, from an unknown point, between three points whose coordinates are known. Ideally, you observe the angles via a theodolite (transit). Failing that, a sextant. Failing that, a compass, as you state in the question. The means of solution is ...


2

It is possible and to explain why consider the following question. Is the angle formed by the red or by the green lines larger? Trick question! The angles are identical. You see, if we have our two points on the map and know the angle between the bearing from us to them, then we can use that information to find the circle that runs through our position ...


1

Split Rock Lighthouse was built in 1910 on the north shore of Lake Superior, near Two Harbors, Minnesota, because all the iron ore in the area (one of the largest deposits in North America) deflected compasses by about 8°. Great ships went down in storms because they got too close to the shore. The Coast Guard retired the lighthouse in 1969. The area was ...


1

Mineral deposits can do this. iron deposits are famed for it. Australia in areas. Is famed for this. Also the area at sea were your compass goes from pointing east to magnetic north to west. Off Australia. It is best to take a upto date magnetic variation chart with you before going to a area. These can be found on line. For free. Just print them off.


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