Take Bearings From a Map
Finding the direction between one point and another is called taking a bearing. Say you want to find the bearing from Owl Pond to Cherry Knoll (left). Place the compass on the map with the long side of the baseplate in line with those two points; the direction-of-travel arrow (A) should point in the direction of Cherry Knoll. Now turn the dial so the meridian lines run parallel to the map’s north-south lines with, importantly, the orienting arrow pointing map north (B). The number at the index line (C) reveals your bearing. In this case, 45 degrees.
To follow that bearing (called plotting the bearing), hold the compass level in front of you and turn your body until the magnetic arrow aligns with the orienting arrow. The direction-of-travel arrow now points toward Cherry Knoll. Proceed forward, making sure the magnetic needle stays on the orienting arrow. In map circles, this process is known as “putting Red [the magnetic needle] in the shed [the orienting arrow] and following Fred” [direction-of-travel arrow].
You DO NOT need to account for declination if you're simply taking a bearing from a map. You need to align either the left or right edge of the map to magnetic (not true) north, and then hold the map in that position and take all the bearings you need.
However, if you try to triangulate, you WILL need to consider declination. For that reason, it is far easier to draw declination lines on your map and take all bearings from those lines. Then you do not need to orient the map towards magnetic north. All you need to do is line up the meridian lines inside the bezel to the declination lines and rotate the direction of travel to your starting/ending points.
Lyn G
May 14, 2011
You don't need to worry about declination if you're taking a bearing from a map and you orient the compass and map to magnetic north. However, if you try to triangulate, you will need to include declination, so it is a good practice to draw the declination lines on the map and always orient with those lines. Also, the only true north-south lines on a map are the right and left edges, a lot of lines on the map are section and township lines which are not necessarily true north-south.
JRS
Nov 12, 2010
You do need to account for local declination whenever you use a map and compass together. The map is aligned to true north, but the compass needle, unless adjusted for declination, is responding to magnetic north. Learn how to orient your map with a compass here: http://www.backpacker.com/backpacking_101_how_to_align_your_compass/skills/12156
Geargeek
Sep 24, 2010
Correct me if I am wrong, but do you not have to accout for the declination of Magnetic North when you go from map to compass?
READERS COMMENTS
You DO NOT need to account for declination if you're simply taking a bearing from a map. You need to align either the left or right edge of the map to magnetic (not true) north, and then hold the map in that position and take all the bearings you need.
However, if you try to triangulate, you WILL need to consider declination. For that reason, it is far easier to draw declination lines on your map and take all bearings from those lines. Then you do not need to orient the map towards magnetic north. All you need to do is line up the meridian lines inside the bezel to the declination lines and rotate the direction of travel to your starting/ending points.
You don't need to worry about declination if you're taking a bearing from a map and you orient the compass and map to magnetic north. However, if you try to triangulate, you will need to include declination, so it is a good practice to draw the declination lines on the map and always orient with those lines. Also, the only true north-south lines on a map are the right and left edges, a lot of lines on the map are section and township lines which are not necessarily true north-south.
You do need to account for local declination whenever you use a map and compass together. The map is aligned to true north, but the compass needle, unless adjusted for declination, is responding to magnetic north. Learn how to orient your map with a compass here: http://www.backpacker.com/backpacking_101_how_to_align_your_compass/skills/12156
Correct me if I am wrong, but do you not have to accout for the declination of Magnetic North when you go from map to compass?
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