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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 ...

24

Isolation and prominence are the two key criteria to classify a peak as an independent mountain. To understand the meaning I like the visualization from the German Wiki where "Dominanz" means isolation and "Schartenhöhe" means prominence: Isolation is the distance to the next point with the same height (radius) of a higher mountain. So the nearest ...

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. ...

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.

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

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 ...

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 ...

7

Prominence Is it's height above the surrounding ground (so the ground level is x height above sea level, the mounting is y height above sea level, it's Prominence = y -x) Isolation Is the distance between it and the nearest point at the same height. This is all based on the "footprint" on a map of a peak. This can be straight forward, or it can be very ...

7

First things first you aren't going to be able to get longitude without an accurate clock and/or a tome of sight reduction tables. Without those aids which you'd be hard pressed to create while marooned on an island your navigational options are limited. The best you can really hope for is to follow a latitude line/plane. I think a cross staff would be an ...

6

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 where the correction can be at least 15 degrees. This is because the magnetic north pole lies somewhere in northern Canada, so the UK is relatively far away for ...

5

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 are half a dozen north poles and most of them move around regularly and they move a lot (10s and 100s even 1,000s of miles/kilometers). Wandering of the ...

5

First things first. You need a sailboat in order to sail. A raft isn't navigated. It drifts and is blown around. If you have a sailboat you already have the navigation tools you need or at least most of them. Any tools that you can make on an island with a pocket knife will be no better than just looking up and recognizing the stars. The level of accuracy ...

4

Ignoring the difficulties of travel (in summer you may need a boat, in winter, skis), then the current weather will make more difference then the season. Given the correct time and standard navigation tables, you can get the latitude by measuring the angle from the horizon to the limb of the sun, the limb of the moon, or to a bright star. Winter might allow ...

4

If you aren't drifting, then one item that would be useful is a log. This is as simple as a chunk of wood and a line. Time how long it takes for the log to reach the end of the line. This gives you a consistent idea of your speed at least relative to the parcel of water you are in. A stone on a string acts as a pendulum. This gives you a pretty ...

3

I have the \$0.99 app, "Footpath Route Planner - Running / Cycling / Hiking Maps". ref: https://itunes.apple.com/us/app/footpath-route-planner-running/id634845718?mt=8 I end up using RideWithGPS on the desktop to map all my bike, run, hike routes but if you're looking for just an iOS version, this is certainly the nicest UI and UX that I've found. Both ...

2

Here is what I have found for taking sights in rough seas. Practice Get a feel for how the vessel is rolling so that sights can be timed to when the vessel is at its most stable which will most often be at the top of a wave. Heaving to can reduce the motion. Take multiple good sightings and average the results. Knowing which sightings are good comes with ...

2

You can't ignore the difficulties. Those difficulties are precisely what dictated when you could attempt the trip. For the most part, those limitations still exist. However for the actual calculation and finding of the North Pole, that would be night time, when you could calculate how far away from the pole you actually were, and also whether you are ...

2

We could get really complicated with this. But basically, magnetic north is a mostly fixed place on the surface of the earth. It's actually moving, but very slowly. Sometimes the map you have may have two compass circles on it. One inside the other. The inner circle identifies magnetic north, and the outer circle identified true north. In addition, the map ...

2

At night it is very easy to find true north using the stars (true south doesn't quite have an equivalent.) First identify Ursa Major, the Great Bear or Big Dipper. Then take the two stars at the end of it away from the handle, and follow the line they make for 5 times its length. The star you hit is Polaris. Head towards it and you are heading towards true ...

2

According to the Mountaineering Council of Scotland, reversed polarity in compass needles is becoming a significant source of navigation error. The reason is the increasing range of magnetic fields in our transport, clothing and equipment. Polarity Issues: the Symptoms With partial polarity reversal the needle becomes sluggish and skittish. With full ...

1

In the UK the prevailing wind blows from the south west and trees/ bushes grow away from the wind so assuming one can see a tree it should be easy to determine the other points of the compass. Elsewhere in the world it would be sensible to determine the direction of the prevailing wind prior to setting out.

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