PDA

View Full Version : A little help on using a compass



aurora_wolf212
02-06-2023, 11:56 AM
Can someone help me use a compass real quick.

Okay so I don't have an adjustable declination compass, wish I knew that before I bought a cheap one, but now I don't want to buy another one.

So I have a few questions I'll just mark them 1 through whatever.

1) To adjust for declination, let's say the declination is 15degrees E, do you turn the bezel counter clockwise 15 degrees, or do you turn it to the right clockwise 15 degrees?

2) let's say you need to set declination, and you have a bearing.. do you add the two numbers together and head in that direction? ORRR do you subtract the declination number from the bearing? I'm confused here. For example, say I head along a bearing of 50 degrees, and the declination is 15 degrees E, do I head to the bearing of 35 or do I head 65 degrees?

kyratshooter
02-06-2023, 01:05 PM
https://www.ncei.noaa.gov/products/magnetic-declination

Your Googlefu is weak Grasshopper.

Rick
02-06-2023, 04:45 PM
A couple of more reads for you.

Magnetic North Pole (wilderness-survival.net) (http://www.wilderness-survival.net/forums/showthread.php?6956-Magnetic-North-Pole&highlight=compass+declination)

Magnetic Declination -- Compass skills (wilderness-survival.net) (http://www.wilderness-survival.net/forums/showthread.php?24205-Magnetic-Declination-Compass-skills&highlight=compass+declination)

Compass Declination by Zip Code (wilderness-survival.net) (http://www.wilderness-survival.net/forums/showthread.php?27095-Compass-Declination-by-Zip-Code&highlight=compass+declination)

Good luck!!

aurora_wolf212
02-06-2023, 09:06 PM
https://www.ncei.noaa.gov/products/magnetic-declination

Your Googlefu is weak Grasshopper.

haha I did google some, watched REI video on youtube and stuff.

aurora_wolf212
02-06-2023, 09:06 PM
A couple of more reads for you.

Magnetic North Pole (wilderness-survival.net) (http://www.wilderness-survival.net/forums/showthread.php?6956-Magnetic-North-Pole&highlight=compass+declination)

Magnetic Declination -- Compass skills (wilderness-survival.net) (http://www.wilderness-survival.net/forums/showthread.php?24205-Magnetic-Declination-Compass-skills&highlight=compass+declination)

Compass Declination by Zip Code (wilderness-survival.net) (http://www.wilderness-survival.net/forums/showthread.php?27095-Compass-Declination-by-Zip-Code&highlight=compass+declination)

Good luck!!

Hey the picture in your first link is not there. Do you still have the picture? I'll try to google best I can based off info you provided in the post. Great post btw, that's the kind of information I'm looking for!

Winter
02-07-2023, 12:35 AM
2) let's say you need to set declination, and you have a bearing.. do you add the two numbers together and head in that direction? ?

How did you acquire that bearing? If you gleaned it with your compass, it's that and doesn't change. If you plotted it off the map, thus using grid north as reference, you will need to convert.

When converting magnetic to grid with easterly declination, you add the declination. Going grid to magnetic, with an easterly declination, you subtract it.

Have you learned how to set the map to your compass?

Well, I'll tell ya, after that you can go to the introduction forum and introduce yourself.

Throw your map on a flat service. set your compass on the map with one of it's straight sides lined up with the North South grid lines.
Now rotate the map till your needle aims parallel to the grip lines. Now rotate the map until the North needle aims 15 degrees east.

You have now oriented your map to your compass. The map is laying as the earth lays. The needle is pointing at a giant lump of iron in Canada. Whatever is north of your location on the map is north of you where you stand, If you see a mountain on the map, look up in that direction and that's where it will be.

Stare at all that for a little bit. The rest of the answers will come to you.