Master Navigator™ Series — Part 5

Determining Direction: How to Shoot an Azimuth with a Compass in the Field

Indexing and following an azimuth on all three compass types (baseplate, lensatic, mirror), shooting an azimuth to a landmark, and the field discipline that keeps every bearing accurate.

By Joshua Enyart · Founder & Head Instructor, Gray Bearded Green Beret

Former Army Ranger, Green Beret, and full-time survival instructor · three decades of professional instructor experience

Knowing where north is on paper means very little if you cannot transfer that direction to the ground under your feet. That transfer — from map to terrain, or from observed feature to recorded bearing — is what we call determining direction in the field, and it is the first working skill a navigator has to build after learning to read a map.

This guide covers how to shoot an azimuth with a compass in the field, how the technique changes across the three compass types, and how to pull a direction out of the landscape when you do not have a map in front of you. It is the fifth post in our Master Navigator™ Map Reading and Land Navigation cluster, paired with Part 5 of the Master Navigator™ PDF Series.

Field Direction vs. Map Direction

Map-table work — orienting a map, using a protractor, converting grid azimuths to magnetic azimuths — is a planning skill. It happens at a flat surface with coffee next to you. Field direction is what happens when you stand up, fold the map away, and start walking.

In the field, the compass stops being a measurement tool on paper and becomes a steering wheel. You index a number into the bezel, orient the compass to magnetic north, and then turn yourself until your body is lined up with that direction. From there, every step you take points at the next leg of your route. Mastering the specific sequence of getting from a planned number to a line on the ground is what separates a navigator from someone with a compass in their pack.

Index and Follow an Azimuth

The first of two core field skills is indexing a known azimuth — say, 316° magnetic — and using your compass to actually walk it. The exact motion depends on which kind of compass you carry, but the principle is the same across all three: dial the number in, align the needle, pick a distant reference point, walk to it, repeat.

Baseplate Compass — Center Hold Method

The Center Hold is the fast, gross-refinement technique for most open terrain. Rotate the bezel until your azimuth lines up with the index line, then hold the compass flat at chest level with your elbows tight to your sides. Turn your whole body until the red magnetic needle is seated inside the orientation arrow — what navigators call “red in the shed.” Lift your eyes off the compass, find a distinct reference feature on that line, and walk to it. When you arrive, repeat.

Lensatic Compass — Compass to Cheek Method

A lensatic compass supports both the quick Center Hold and a second, more precise technique called Compass to Cheek. Use Center Hold for speed on open ground, then transition to Compass to Cheek when you need the tighter bearing — for example, when your distant aiming point is a specific tree in a cluster of trees, or when you are about to cross a long, featureless stretch where drift adds up. You sight through the rear slot and align the front wire on your target while reading the azimuth through the magnifying lens. It is slower, and it is worth the extra second.

Mirror Compass — Full Presentation Method

A mirror compass (the Suunto MC-2 is Joshua’s reference) gives you the same trade-off in a different form. Center Hold gets you close; the Full Presentation gets you precise. With arms extended and the mirror tilted so you can see the compass housing, you sight through the notch in the cover at your target, then use the mirror to watch the needle seat inside the orientation arrow. It is the most refined of the three field techniques, and it is the one worth practicing until it is automatic.

Full step-by-step procedures for all three compass types — including the thumb-and-index-finger setup for the lensatic and the exact sequence for the mirror presentation — live in the PDF.

Determine an Azimuth from Observation

The second core skill is the reverse: you see a feature out in the landscape — a ridge, a tower, a far edge of a lake — and you want to capture the direction to it as a number. That number can then be recorded, plotted, or walked later. The procedure on each compass type is essentially the first skill run in reverse.

Point, Align, Read

On a baseplate compass, you face the target directly and rotate the bezel until the orientation arrow seats itself under the magnetic needle — the shed moving to the red, rather than the other way around. Read the number at the index line, and that is your magnetic azimuth to the feature.

On a lensatic, you do the same thing with a Compass to Cheek sight picture, reading the azimuth at the black index line through the magnifying lens. On a mirror compass, you use the Full Presentation to sight through the cover while watching the needle in the mirror, then rotate the bezel so the orientation arrow captures the needle. The refinement is the same in every case: the tighter your sight picture on the target, the more accurate the azimuth you record.

Always Label Your Azimuths

Every azimuth you write down in a field notebook or a Route Planning Log should be labeled as either magnetic or grid. Magnetic is what your compass gives you directly. Grid is what the map works in. The LARS rule (Left Add, Right Subtract) is what converts between them — and that rule lives on the map-reading side of the curriculum. If an azimuth in your notes is not labeled, you will not remember three hours later which reference frame it came from, and a converted azimuth converted a second time is a guaranteed mistake.

Why the Technique Matters More Than the Compass

All three compass types will get you where you are going. What separates a reliable navigator from an unreliable one is not the brand on the bezel — it is the discipline of running the same technique the same way every time. Index, align, walk. Point, align, read. The compass is only as accurate as the hand holding it, and the hand is only as accurate as the number of repetitions behind it.

One specific failure mode worth flagging: holding the compass near a metal belt buckle, a firearm, or the steel frame of a pack can pull the needle off true magnetic north by several degrees. Arm’s length, chest height, and away from ferrous metal is the baseline posture. Wristwatches, headlamps, and phones with magnetic cases all do the same thing. Train the habit of noticing them.

Common Mistakes When Shooting an Azimuth

A few errors come up over and over in courses. Watching for them is cheaper than fixing them mid-route.

Wrong reference point. Picking a distant aiming point that looks distinct from where you stand but blends into the terrain as you approach it — a single pine inside a pine forest, a single rock inside a boulder field — means you will lose it halfway there and your azimuth walk falls apart. Pick a feature that reads differently from everything around it.

Needle not seated. The magnetic needle has to be centered inside the orientation arrow, not close to it. “Red in the shed” means fully inside. A needle that is only partially inside the housing reads a few degrees off, and a few degrees over a thousand meters is hundreds of meters of drift.

Forgetting to label. Any azimuth that gets written down without a magnetic-or-grid label is an azimuth you will misread later. This is the single most common notebook error in land-navigation courses.

Drifting the compass between bezel and walk. Once you have aligned the needle, your job is to look up, fix the reference point with your eyes, and walk. Looking back down at the compass mid-stride and re-rotating your body is how people introduce lateral drift into a straight-line movement.

Pairs With the Rest of the Kit

Determining direction in the field works because the other pieces of the Map Reading and Land Navigation Kit are doing their jobs too. The map gives you the starting azimuth. The pace count gives you the distance for that leg. The notebook and pencil give you a record of every azimuth you shoot and every feature you intersect. The protractor (or the scales on a mirror compass) lets you plot a field-shot azimuth back onto the map when you stop to check yourself.

Direction is one of three legs of the field-navigation tripod. Distance is the second, route planning is the third, and all three show up in the next three posts of this cluster.