# Tag Info

41

If you look at the current time, and imagine yourself in the center a big analog watch, just place your shadow on the location of the hour's hand. Then imagine the location of the 12 o'clock hand, and exactly in the middle of the angle between those two hands is the north. Be sure to ignore daylight saving time (As the time your hand watch is showing during ...

40

This map (and the Wikipedia article) will explain why you don't have a problem (in the UK, I'm guessing), but others do, elsewhere. In the UK, you can ignore it at the moment, but you need to understand WHY you're ignoring it :) As an aside, compare this with the declination in 1872... Then, the declination error in the UK would have been between 20 and ...

32

Compasses are good equipment both spelunking and diving. Even the deepest cave you could go to is still near the earth's surface, geologically speaking. The earth's magnetic field is also essentially the same under water as above. If you are using a compass, what you need to be aware of is nearby magnets and large sources of iron. So if you were exploring ...

29

If there's a stick around and enough sunlight, I've found the stick method surprisingly accurate: Find a straight stick, around 2 feet long (length isn't that important) and plant it straight in the ground. Mark the end of the stick's shadow, perhaps with another short stick. Wait for about 15 minutes then repeat step 2. Draw a line between the two ends ...

28

There seems to be a fixation with North in navigation. Step back to the basic purpose, why do we navigate? We navigate to get to somewhere or to find our way back. Knowing north is just one method of doing such. So predicating navigation on knowing which way is north is unnecessary. North isn't the goal, it's a reference for finding what you really want....

24

This depends highly on your location. Contrary to popular belief, the difference between the magnetic pole and the geographic pole is not the only reason for declination. As a matter of fact, the magnetic poles are simply defined as the points where the magnetic field points vertically. This is not the same as the pole of a anyway non-existing earth-magnet. ...

23

With fog, the only thing you're losing is extended visibility. This shouldn't throw off your plan too much, unless you were navigating by watching far away landmarks. If you were on a trail, stay on it. There's no need to wander around. If you can't see anything and traveling is becoming dangerous or you're not sure where you're going, then stop and wait ...

22

Where your magnetic compass points can be quite far away from the north shown on your map For example, on the line marked 30, your compass would point 30 degrees away from true north.

19

If you need to walk on a compass bearing in poor visibility, stand still, and send someone out in front of you on the correct bearing for a distance (probably as far as you can see). Have them stand still, then walk to them. Repeat. It's slow going, but you will be walking on the correct bearing, and more accurate than just holding the compass out in front ...

16

Basic celestial navigation: In the northern hemisphere, the star Polaris indicates north. In the southern hemisphere, you can use the Southern Cross, see Finding the south celestial pole.

16

Yep! If you store your compass near objects that have strong magnets in them (such as your car speakers) it can demagnetize over extended periods of time. There are a few other issues your compass can run into that makes it less reliable as well. Air getting into the compass housing (in excess) Bubbles can form within the compass housing when doing big ...

16

Magnetic pole The distance from the rotational north pole varies over time -source By the time you read this, the north magnetic pole could be half the circumference of the planet away from the true (i.e. rotational) north pole. Thats over 20,000 km apart. It has been in the past. See magnetic pole reversal and rate of transition. Declination More ...

15

The distance between the magnetic north and geographic north poles is not important for navigation purposes. What matters is the angle between them, which is called the magnetic variation or magnetic declination. The magnetic variation varies depending on where you are on earth, and also changes slightly from year to year. In Pittsburgh, Pennsylvania, it'...

14

They're absolutely NOT the same thing. The distance varies. But it's about 500 miles. (http://www.livescience.com/41955-north-pole.html) Since its discovery in 1831, the magnetic North Pole has been around Canada’s Ellesmere Island, about 500 miles (800 kilometers) from the geographic North Pole. https://en.wikipedia.org/wiki/True_north

14

According to this site there are only a few things that can go wrong with your compass: Mechanically, it can become hard to read because of a cracked dome or contaminated fluid; it can leak, causing a bubble in the fluid which, if allowed to grow, will interfere with damping of the dial; or it can become “sticky,” a condition that prevents the card from ...

12

There are several ways to determine true north, especially when you have a map and compass: Competent maps, like most intended for backcountry hiking, will have the magnetic declination marked. This is usually in one of the corners. Take a look at any USGS topo map, for example. The compass will tell you the direction to magnetic north, and the map tells ...

11

The only reliable information I seem to be able to find points to the fact that if you store a compass next to a strong magnet for a long period of time, it can wreck it. Additionally, it seems that some people have reported their compass becoming demagnetised when stored adjacent to something like a phone, headphones etc. though this appears less common. ...

11

If it's early morning, you'll note that the sun rises in the east. It additionally sets in the West. Normally, more plant-life can be found on the east side of a ridge (I don't have a source for this, I'm sure someone else can be more helpful) as it more fully receives light. Personally, I navigate almost exclusively by features and carry a contour map with ...

10

The distribution of sun east / west should be pretty close to the same. In the northern hemisphere, the south side of areas gets more sun due to the sun being more to the south (perpendicular to the equator). This doesn't necessarily translate into there being more vegetation on the south side of ridges though, it depends on the environment. Southern ...

10

Lensatic Compasses are often used by the military, because the are: Reliable Durable Compact Stealthy (more on this) The things that I would look for in a lensatic compass are: Solid outer casing Sighting guide with thin slot or notch Compass latching cover. Electrically buffered needle Some lensatic needles are buffered with oil, which can leak. ...

10

What you describe is exactly how it was done: Accurate measurement of distances and angles Obviously, measuring distances on flat ground is relatively straightforward: you use a known length measurement (perhaps a robe marked at known intervals); and to measure the distance to a distant point, use two points and a bit of geometry (Pythagoras is helpful ...

10

Olin Lathrop's very good answer to the question you reference basically already contains most of the information needed also your gut feeling about the topic is quite right. So let's look at it in a bit more general way: Keeping your compass declination in mind gets the more important, the closer you are to one of the magnetic poles, the more you travel ...

9

While Rory Alsop's answer points exactly to the method followed by cartographers and geologists before the invention of GPS and other modern techniques, I'd like to make a point that it was done with an assumption that they knew what altitude they are at and when you stand at planar location located from a mountain at a known distance and you can figure out ...

9

Pacing and timing can be used to aid navigation in poor visibility. Both methods improve as you gain experience by practicing pacing and timing over different terrains. Pacing by counting steps (beads on your compass lanyard or a mechanical counter will help you avoid loosing count) to estimate distance travelled from a known location. Timing based on, for ...

8

When I go off-trail into the woods, I bring a topographic map, compass and GPS with me; of the three, the one I use least is the compass and the one I use most is the map, because I have learned to read the terrain and match it to the map. Even if you know which way is north, that may be very little help in knowing where you are, how to get where you want ...

7

The topics of navigation and cartography are two sides of the same coin, and there are entire books written about each. It is interesting to study the history of cartography because it very graphically shows the corresponding improvements in navigation over time. In order to make an accurate map, you need to know first where you are making your ...

7

A compass is "accurate" in both hemispheres in that it should still point to magnetic north. But the problem is that when you're in the southern hemisphere, the magnetic north pole is sort of 'under your feet' so the compass needs to be one that's specially 'balanced' for the Southern hemisphere to ensure the needle moves smoothly and responds fast. You ...

7

Depending on the terrain, a map is often very usable even without a compass or a GPS. If the terrain is anything-but-flat you can generally use the contours of the terrain to orient the map correctly. "Walk down this valley until it branches, then head for the mountain aproximately 30 degrees left." doesn't require a compass. Learn to read contour-lines on ...

7

There's a whole bunch of standard map and compass techniques you can use without a GPS. If you know your location before the fog came down, then you're not lost - you just can't see so far. Change your navigation strategy to have shorter legs, and pick tick points that will be within your vision. Pay particular attention to changes in trail direction and ...

6

This depends of course on the tools you have and what your overall situation is. For example, if you know that you are on a certain path and you have a compass, and if you are on a slope, you can try to figure out the direction of the slope and compare that to the slopes along the path you are on using your topographic map.

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