LandNav 101: Compass Selection and Recommendations

by October 11, 2010 10/11/10
LandNav 101 Compass Selection
4 of 6 in the series LandNav 101

Today we are going to continue from our last article on Reading and Associating Terrain and discuss compass selection for use in land navigation.

Compass selection is often driven by personal preference, much like some prefer one vehicle make and model to another.

Our goal with this article is not to suggest which compass to buy before you know how to use it, but rather to show you the different options out there. We feel it’s important and necessary to have a compass at your disposal during this series.

Categories

Many manufacturers will often group their compasses into three categories: professional, sports, and recreational. In reality, there are effectively only two broad categories of compass types: clear base plate models used for orienteering and lensatic compass, effective for distance sighting with mirrors.

Virtually every book and instructor will go out of its way to point out that in experienced hands, either type of compass can be highly effective–a point worth emphasizing here. As this series is about getting back to basics, we aren’t going to cover the plethora of digital compass solutions that have shown up in the market over the last half-dozen years.

Why? Because batteries fail and you should always have a “manual” compass with you anytime you are relying on a digital one, including GPS!

Manufacturers and Features

Three of the dominant compass manufacturers include Suunto, Brunton and Silva. Between the three of them, there are about 40 different compass models to pick from, each with a different combination of features.

Let’s take a look at the features available on compasses and what you should look for in the compass you choose to purchase.

Base Plate

A no frills base plate compass, like the Brunton 7DNL ($15.00 list) or the Silva Starter 1-2-3 (list $9.99), are simple compasses that provide the navigator with the basic essentials and no more.

These essentials include an orienting arrow with orienting lines, a degree dial bezel at 2 ° graduations, and usually one or more scales or rulers along the edges of the compass.

In contrast to these base plate models, middle-tier models like the Silva Explorer Pro (list $27.99) provide additional features that simplify land navigation tasks. For example, on long journeys at certain latitudes forgetting about magnetic variation (declination) can be very costly.

The basic models provide a declination scale, but lack the ability to physically adjust the compass so that it operates at a given declination. The Explorer Pro is a compass that provides a gear driven adjustment mechanism. If you’re going to purchase a new compass, this is a highly recommended feature.

Global

Further up the price tree are base plate models like the Suunto M-3 Global (retail $42 @ Amazon.com). This compass includes anti-slip rubber pads, a magnifying lens, and luminous markings for those occasions where you’re moving at night.

One unique marketing feature that Suunto promotes is that many of their compasses operate against two geographical balancing zones. These balancing zones are important because the vertical intensity and direction of the earth’s magnetic field fluctuates as you move around the globe.

Ensuring your compass is properly balanced for the part of the world you are going to use it in cannot be an afterthought. In Suunto’s case, they have balanced most of their product offerings for two zones, instead of the five zones that the globe is typically sliced into. If you don’t plan on heading over the equator, you’ll only need to purchase a compass balanced for the northern hemisphere.

Adventure Racing

Brunton offers the 8096-AR, a compass marketed explicitly toward adventure racers. The base plate includes a latitude, longitude and UTM template for critical details, but it lacks in two areas. I speak from first-hand experience.

The 8096 compass was intentionally designed without orienting lines, and the circle-over-circle alignment system isn’t very user friendly. Judging if the circles are properly aligned can lead to a 2 ° to 4 ° degree variation.   That makes a HUGE difference on long waypoint hikes.

The bottom line: unless you are using this compass to compliment a GPS, taking advantage of GPS features (like the five confidence circles along the edge) this compass is outright hard to use with a map. Keep this in mind if this compass makes your short list.

Lensatic

The lensatic compass differs from the base plate model in many ways. First, instead of a clear and rigid plastic base, the lensatic compass has articulating pieces, including a cover that protects the floating dial.

Second, the lensatic compass comes with a sighting mechanism for navigating across great distances by shooting headings at distant landmarks. Shooting headings is possible with a base plate, but the lensatic allows the user to line up very specific targets using its sighting lens.

 

Most base plate compasses provide 2 ° increments on their dial, while lensatic compasses contain 120 clicks when rotated fully; each click represents a 3 ° shift. Instead of looking down directly at the floating dial, the user relies on the lens to read the dial.

Recommendations

Admittedly, it has been years since I’ve worn a uniform and used a lensatic compass like I was trained on back in the day. My transition to civilian life included switching over to a base plate compass.

My personal preference in a compass is a simple base plate model, complimented with the MadAthelete.com UTM plotter, available at Amazon.com for the meager price of $7.50. This plotter is the size of a credit card and convenient to carry. If you’re still using MGRS as your primary navigation means, check out the MGRS/UTM Coordinate Grid Reader & Protractor instead for $6.95.

To reiterate an important point from the introduction, either compass in experienced hands will get results. The key to this sentence is experienced hands.

Notes

If you’re confused on some of the features we’ve described, we’ll be getting into how to properly use them in a future article in this series. Each of the articles in the LandNav101 series are building blocks and are to remind each of us that land navigation is a perishable skill. Learning to use a compass and then letting it collect dust for 5 years does not equate to experienced hands regardless of the compass category.

Next week we are going to formally introduce the UTM grid. We’ll be using our topo map for Sam Houston National Forest, a base plate compass with orienting lines, and the handy UTM plotter.

The LandNav 101 series is using the Sam Houston National Forest as the training grounds for most of its cartographic adventures. If you’d like to download a PDF of the referenced topo map, it is the Huntsville 7.5 x 7.5 1997 map. It has an alternate ID of TTX1823, ISBN 978-0-607-93473-1. A printed version can be purchased from the USGS Store for $8.


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Adrian
Adrian

What about the Recta DP series? They're not cheap, but Swiss built, quality compasses. I've been using a DP6 for a number of years, never let me down yet.

Justin
Justin

Don't rely on your maps declination. go here and type in the zip code of where you'll be. As I have posted in another thread, magnetic declination doesn't change in a predictable, systematic fashion. http://www.compassdude.com/compass-declination.shtml

Remember maps are usually outdated. Disregard if you live in Mississippi :).

Looking for a lensatic compass at the moment I think they're great!

Justin
Justin

Don't rely on your maps declination. go here and type in the zip code of where you'll be. As I have posted in another thread, magnetic declination doesn't change in a predictable, systematic fashion. http://www.compassdude.com/compass-declination.shtml Remember maps are usually outdated. Disregard if you live in Mississippi :). Looking for a lensatic compass at the moment I think they're great!

Crooks
Crooks

I'm with Just a Scout, in my views the Cammenga USGI Tritium Compass is by far the best.

Just a Scout
Just a Scout

I still like the old Camenga Tritium military model the best.

Woody
Woody

Silva Ranger 515 CL or Suunto MC-2G....haven't failed me in over 10 years. Just upgraded to the Suunto a few years back. I NEVER travel without a compass and map, call me old school but if the skill works, why not have the tools for it.

Pig Monkey
Pig Monkey

I'm not a big fan of adjusting compasses for declination. I started out doing it that way, but I found that it made me too lazy.

For the areas that I most frequently travel, the grid-to-magnetic declination is 15E. So I would set that in my compass and forget about it. For most of my trips in the same area I would never have to think about declination. Then I would go somewhere where the declination was significantly different and, well, you can guess the rest of the story!

Now I always keep my declination ring at 0. I perform the calculations mentally. This means that whenever I have the compass out, I'm constantly thinking about declination. For me, it's a much safer practice.

Pig Monkey
Pig Monkey

I'm not a big fan of adjusting compasses for declination. I started out doing it that way, but I found that it made me too lazy. For the areas that I most frequently travel, the grid-to-magnetic declination is 15E. So I would set that in my compass and forget about it. For most of my trips in the same area I would never have to think about declination. Then I would go somewhere where the declination was significantly different and, well, you can guess the rest of the story! Now I always keep my declination ring at 0. I perform the calculations mentally. This means that whenever I have the compass out, I'm constantly thinking about declination. For me, it's a much safer practice.

Bryan Black
Bryan Black

PM, I've been trying something fairly similar. As I'm traveling to different "declinations" (I like the term magnetic variation, as that's what it truly is) as well, I've just gotten in the habit of leaving mine at 0 as well and manually setting it based on the topo I'm looking at. I do like the gear function in a compass to set it, but have found I've forgotten to perform calculations mentally before and can't trust myself!

Good addition and comment!

Bryan Black
Bryan Black

PM, I've been trying something fairly similar. As I'm traveling to different "declinations" (I like the term magnetic variation, as that's what it truly is) as well, I've just gotten in the habit of leaving mine at 0 as well and manually setting it based on the topo I'm looking at. I do like the gear function in a compass to set it, but have found I've forgotten to perform calculations mentally before and can't trust myself! Good addition and comment!

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