61
votes
Accepted
I never adjust for true north. Is this bad practice?
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 ...
- 3,906
41
votes
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Compass compatibility: Can I use my US compass in Australia?
I double checked a couple of websites (thanks a lot for the comments to the question) and I'm sure that my compass is not compatible with Australia.
As a result of these magnetic variances, the ...
37
votes
Will a compass work underground or underwater?
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 ...
- 4,199
30
votes
I never adjust for true north. Is this bad practice?
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.
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30
votes
I never adjust for true north. Is this bad practice?
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 ...
- 21.6k
21
votes
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How much distance is there between True North and Magnetic North Poles?
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 ...
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19
votes
How much distance is there between True North and Magnetic North Poles?
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 ...
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19
votes
Compass compatibility: Can I use my US compass in Australia?
Having used my Europe compass in America as well as in Australia, I would say you do not need a new one.
It will still point one end of the needle to the north and the other to the south, only the ...
- 2,557
18
votes
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Can a compass needle become de-magnetized over time?
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 ...
- 1,524
17
votes
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I have a compass but no watch, how can I tell when it will get dark?
You don't need a compass, nor any mechanical tool at all. You just need your fingers. I've linked an article with illustrations at the end, but here is the basic idea:
Stand facing the sun, extend ...
- 5,158
17
votes
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What purposes does a physical compass serve better than a compass application on my cellphone?
A phone app lacks many features that compasses have which are essential to orientation. Among the main ones:
A transparent casing that makes it possible to read the map through the compass and align ...
- 4,976
16
votes
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Calculate true north with a compass and map
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 ...
- 21.3k
16
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I never adjust for true north. Is this bad practice?
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 ...
- 7,502
15
votes
Accepted
Should you store a compass flat?
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 ...
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14
votes
How much distance is there between True North and Magnetic North Poles?
They're absolutely NOT the same thing.
The distance varies. But it's about 500 miles. (The North Pole: Location, Weather, Exploration … and Santa).
Since its discovery in 1831, the magnetic North ...
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13
votes
How did people make topographical maps in the pre-modern?
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 ...
- 31.5k
13
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How did people make topographical maps in the pre-modern?
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 ...
- 24.4k
13
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Is it normal for a compass to develop an air bubble at high altitude?
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 ...
- 68.9k
13
votes
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How to identify latitude & longitude with a compass?
You need something else.
You need a sextant and a marine chronometer (a fancy watch). The sextant measures the inclination of a star or the sun, and helps to determine latitude. Once you know that, ...
- 5,158
12
votes
Are there types of compass other than the regular magnetic one and the gyrocompass?
Beyond the ones you have mentioned, there are,
Solar Compasses
The solar compass, a surveying instrument that makes use of the sun's direction, was first invented and made by William Austin Burt.1
...
- 68.9k
12
votes
When using a compass, why not follow a degree mark without rotation?
The old style pocket compasses worked just like that.
The problem: If you use a compass without using that arrow -- just using the degree marking on the dial, your error will about triple.
If ...
- 11.8k
11
votes
Accepted
Can a compass be thrown off by its surroundings?
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 ...
- 68.9k
11
votes
Are there types of compass other than the regular magnetic one and the gyrocompass?
There are some very crude outdoor compasses which tell us the direction of true north (and assume we can estimate angles from north). The following also assume we're in the northern hemisphere.
A sun-...
- 3,855
11
votes
Accepted
What is dead reckoning when navigating with a map and compass?
What is dead reckoning?
Dead reckoning is the skill of moving along a specific bearing for a specific distance - eg, to walk 350 meters on a 25 degree bearing - without reference to any major feature ...
- 11.6k
11
votes
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What are the differences between prismatic, lensatic, mirrored, and optical sighting compasses?
The typical protractor-style compass is an optical compass. To shoot an azimuth with it you align marks on the compass and read the bearing off the dial. The other varieties have a sighting wire which ...
- 556
10
votes
Offset in compass
Adjusting Declination
According to the maker that compass has "tool-less declination compensation" - so you should be able to correct that for local magnetic declination
The video on their webpage ...
- 787
9
votes
Accepted
How did cartographers map out shores before modern times?
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 ...
- 1,738
8
votes
I never adjust for true north. Is this bad practice?
Not discounting the existing answers which provide great perspectives. You don't really care where the North Pole is. It is not like there is only one or two, nor is like anything is stable. There ...
- 30k
8
votes
I never adjust for true north. Is this bad practice?
As others have said the importance depends on your location. In the UK & Europe the correction is quite small, approx 2-3 degrees and can therefore mostly be ignored. Compared to parts of the US ...
- 7,069
Only top scored, non community-wiki answers of a minimum length are eligible