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Map & Compass: Find & transfer bearings in the field & on a map

This is the second of a 7-video instructional series from Sierra Designs. This one, as well as the first, are dedicated to map and compass, which is a subcategory of navigation. If you haven’t already, learn to adjust for declination and to orient a map. Got it? Good, let’s move on to a more advanced lesson.

Real world examples

Before I explain how to find and transfer bearings in the field and on a map, I’d like to share two real examples in which having this know-how would be useful.

1. You are section-hiking the Kings Canyon High Basin Route, which is largely off-trail. From Dumbbell Pass you believe that you can see Observation Peak, which is an important landmark because your next pass (Amphitheater Pass) is immediately to its east. You find the bearing to the mountain that you believe is Observation Peak — 345 degrees. You then transfer that bearing to the map and, indeed, Observation Peak is at 345 degrees from your current position at Dumbbell Pass.

From Dumbbell Pass, Observation Peak Pass is at 345 degrees. The next pass, Amphitheater, is below it on the right side. The Palisades loom in the background.

From Dumbbell Pass, Observation Peak Pass is at 345 degrees. The next pass, Amphitheater, is below it on the right side. The Palisades loom in the background.

2. You are climbing New Hampshire’s Mount Washington in March. Conditions are mild, but it’s a whiteout (of course) and the trail above Lake of the Clouds Hut is buried under snow. To reach the summit, you find the bearing on your map between the hut and the summit — exactly 45 degrees. You transfer that bearing to the field, and begin to hike in that direction.

To reach Mt. Washington from Lake of the Clouds Hut in a whiteout, take a bearing on the map (45 degrees) and transfer it to the field.

To reach Mt. Washington from Lake of the Clouds Hut in a whiteout, take a bearing on the map (45 degrees) and transfer it to the field.

Of course, my compass is not my only navigational tool, and rarely do I rely on it exclusively. For example, before hiking over to what I believe is Amphitheater Pass, I would double-check the mapped topography of Observation Peak. And while climbing to Mt. Washington’s summit, I would keep an eye on my altimeter. If there is inconsistency between my data sources (i.e. my compass, map, altimeter, clock, GPS), I stop and figure it out.

Also, these examples do not represent the extent of real world uses. Once you know these techniques, you’ll realize that there are countless situations in which you can apply them.

Actions and worlds

Two actions are possible with a compass. You can:

  • Find a bearing, a.k.a. take or spot a bearing; and,
  • Transfer a bearing, a.k.a. transpose or plot a bearing.

You can find and transfer bearings in two different worlds:

  • The field, i.e. the mountains, lakes, and canyons around you; and,
  • A topographic map, which depicts a landscape in a condensed format.

All told, then, to effectively use a compass you need to learn four techniques. How to:

But it gets slightly more complicated, because in practice you always perform two techniques together. Specifically, you:

  • Find a bearing in the field (e.g. Observation Peak), and transfer it to a map (watch at 5:20); or,
  • Find a bearing on a map (e.g. Mt. Washington), and transfer it to the field (watch at 6:41).

When I teach map and compass on my guided trips, I ensure that the clients can perform the four techniques above before explaining that the steps have to be combined. For example:

  • To learn how to find a bearing in the field, I will have them take a bearing to a tree or a boulder.
  • To learn how to transfer a bearing in the field, I will give them a random bearing, like 68 degrees.
  • To learn how to find a bearing on a map, I will tell them where they are (e.g. “Iceberg Lake,” even if they are not) and where to find a bearing to (e.g. “Point 7554,” even if we’re not going there and I’ve never even seen it).
  • To learn how to transfer a bearing to a map, I again give them random bearings, like 256 degrees.

Once they’ve mastered these four steps, in theory you can combine them. But for it to become second nature, practice is involved.

4 Responses to Map & Compass: Find & transfer bearings in the field & on a map

  1. Jonny Rando August 12, 2016 at 10:12 am #

    Your youtube series on navigation is awesome. Keep up the good work.

  2. MarkL December 1, 2016 at 12:16 pm #

    Very nice, if quick, introduction. As someone who teaches navigation for a backcountry ski patrol, if I may make a couple of suggestions to clarify common errors.

    1: Specify that when you do this work with the map you are finding the TRUE bearing. If you don’t have your compass adjusted for declination (like in part 1) you need to account for that when transferring it to/from the real world. That’s a whole different lesson, but I find it useful to point out things to look out for.

    2: When making the meridian lines parallel on the map, the orienting arrow (shed) needs to be generally pointing north. If you have the meridian lines running the wrong way you will be 180 degrees off.

    3: My most important rule is to have students check themselves whether their answers make sense. If your bearing is supposed 45 degrees (NE), but your compass reads 225 degrees (SW), you have made the mistake from #2 (or drew your line with the compass pointed the wrong way.) If you are supposed to be travelling generally south, but you are facing away from the sun, you may have a problem.

  3. Hunter Hall May 18, 2017 at 2:41 am #

    Silly question, I know, but what jacket is that with the thumb holes? I’ve been looking for a hooded down jacket like that with thumb holes, but can’t really find one I like.

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