Magnetic Or True North

[+Fizzfever]

So which one? How does each effect the results?

[Tahosa and Sons]

Which North to use, well that depends on the cache itself. Some use True and will tell you so. Some use Magnetic and will tell you so. And some of them you will have to figure it out or just get lost.

 

Declination is one of the things that one should know how to adjust if you are going to play with that old chinese tool.

[Major Catastrophe]

If you use a magnetic compass to supplement your GPS, using magnetic north will let you switch back and forth without worrying about declination. For a compass to reference true north, it must be adjusted for the declination in the area where you are using it.

 

I tried using magnetic north but I've used true bearings and kept my compasses adjusted for declination much longer than I've had a GPS. I went back to "true" north because I think better that way. Ultimately, it's a matter of personal preference.

[+The Jester]

One other point: Most road grids in the USA are set up on True north.

 

Interesting historical note: In Seattle, when they were first laying out the streets, they divided the town in thirds with 3 men to lay-out the streets. There was a disagreement between the three, so the center (downtown) is on Magnetic north, the north and south sections are on True. This give some very interesting intersections where the various sections meet.

[+Fizzfever]

Doesn't magnetic north actually shift from year to year, or am I remembering this wrong?

[+GeoCyclist]

You need to read and understand declination. I'm not good enough to explain it here.

 

Magnetic North is what a simple compass gives you. True North is what up on most maps is.

 

Unless you are on a map course most geocaches should matter. A lot of times if a bearing is given they will state magnetic or true.

[+EraSeek]

Rather than repeat everything, please read THIS THREAD.

[+Southview]

Posted: Jul 27 2004, 05:21 AM

 

Premium Member

 

Posts: 11

Joined: 1-June 04

 

 

Brain fuzzelage and smoke streaming from ears and eyes all crossed. The answers every one gave are all fine. But to keep it simple and understandable,you really have to know about using a compass and paper maps. Since paper maps are oriented to "True North", (meaning that if you placed a paper map on the table you want to know which way to turn the map to put the top of the map facing North) The up and down grid lines on a map are oriented to True North, not magnetic north, so when you place your compass on the map and the needle points to north it is pointing to magnetic north, not true north. So you look at the bottom of the map and it will tell you how many degrees difference there is between magnetic and true north, then you can turn your map so that it points to true north, which is in line with the grid lines. Hope this helps! .........PS: GPS units, in there defalt mode, use Magnetic North. You really don't need to change over unless you are dealing with a paper map or the CACHE is given in true north readings.

 

This post has been edited by Southview on Jul 27 2004, 05:32 AM

[+Fizzfever]

Thanks southview, we are trying to learn how to use a compass in addition to the gps. So I did understand your reply. i had been wondering if it was better to change the gpsr default setting to true north. However since it is the default setting most folks use that default setting and it would probably be best to leave it alone, just as you say.

[Keystone]

Rather than repeat everything, please read THIS THREAD.

Or read this even longer discussion, which I found by running a search on the keywords "magnetic north."