Suunto M-3 Global Compass Review

Suunto M-3 Global Compass

In the world of navigation, there are many choices.  These days people often opt for a purpose built GPS or sometimes even a smartphone. While I own these devices, I tend to leave them at home and instead bring along a simple map and compass.  Of course, there are also people who go naked, without any navigation aid, and instead rely on a well marked trail or other known landmarks to get themselves home. That's not for me either - I'm a compass guy.  Among compasses, there are several types - baseplate models and mirror models being the most popular / useful.

The M-3 Global is Suunto's top of the line baseplate compass, and the one I reach for most often.  I recently purchased a new one after my previous one got lost, forgot its own map and compass, and failed to make it home.  What follows is my thorough review.

Features

Two things drew me to this compass.  The first is its ability to settle quickly and remain on point as I walk, jog, scramble, or whatever.  Ever since my first navigating experience back in my scouting days, I've valued this feature.  My first compass was a non-liquid filled job that could rarely remember where North was and when it finally found it was, as they say, "as shaky as a hound dog shittin' peach pits."    This Suunto does a great job of finding North quickly and staying there.  Here's a fun game... pick it up, spin it on your finger like a Harlem Globetrotter spins a basketball, then set it down and watch how fast it settles. 

The next feature that I really love about this compass is that declination can be adjusted with a tiny screw on the back.  A small tool is included on the lanyard to make adjustments.  I'll admit that this is a lazy man's feature - a person can easily adjust for declination with a little math - but hey, I'm lazy and bad at math.  Incidentally, the NOAA has a great magnetic declination tool on their website.

If you count grams, this one weighs 50 g on my scale at home, including the lanyard and all the other stuff.  That's 1.76 ounces if you count ounces instead of grams.  Are there lighter navigation solutions?  Sure, but instead just drill another hole in your toothbrush and then you can bring this one.

There are lots of other little features that make this compass a real joy to use, but honestly it's stuff I expect to have on any decent compass.  Here are a few that come to mind:

• Little rubber feet to help it sit nicely without sliding around on a map
• A magnifying glass to help read said map (or, presumably, start a fire with the help of the sun)
• Map scales for 1:24,000 and 1:62,500 (see this post for my tips on getting free topo maps)
• Marks that allow the compass to be used as a clinometer

And a few that the marketing people probably insisted on, but that provide little value to me:

• Glow-in-the-dark markings (if you can't see the map or where you are going, why does it matter if you can see the compass?)  Presumably you'd either have a light source or decide to stay put
• Control marking holes.  I'm not making orienteering maps, and if I did I'd probably use a different (thinner) material for a stencil.

 

Unboxing 

The Suunto M-3 Global comes in two models, an "inch" version and a "centimeter" version.  The only difference between the two is the map scales that are provided.  Both have inch and centimeter markings, but the inch version has common US map scales, and the centimeter version has common European map scales.  I'm not sure why they don't call it "US" and "Rest of World" version.

Since I do most of my hiking in the US, I purchased the inch version.  If I were to use this compass abroad, I'd simply supplement the compass with any of the readily available map tools on the market.  My Brooks Range tool, for example, includes 1:25,000 and 1:50,000 scales that are common outside of the US.

Suunto M-3 Global Compass Packaging

 

This is a really simple device, and the packaging is quite appropriate for its contents.  In addition to the compass itself, you'll have the lanyard with an plastic spring clip for adjusting its length.  Attached to the lanyard is the small key for adjusting declination.  In addition, the package includes instructions and the warranty (which I discuss below).

Contents of the Suunto M-3 Global Compass Package

Plastic Spring Clip for Adjusting the Length of the Lanyard

Key for Adjusting Declination

(and of course the compass itself)

Taking and Following a Bearing

Whether I'm using it on a map to find or plan a route, or using it in the field to find or follow a bearing, it works just like every other compass.  The M-3 Global has 2° resolution (and Suunto claims that is accurate to the same 2°).  I'm never navigating more than a few hundred yards at a time without taking a new bearing or checking the one I'm on, so I don't ever find myself too far off. 

To test this, I headed out to the fixed course that our local orienteering club maintains.  I was able to navigate exclusively by compass across 14 control points spread over approximately 4 miles. 

I'm not going to go into detailed instructions on how to use a compass here.  There are lots of great resources available - just Google "Put Red in the Shed and follow Fred" and you'll find plenty.  The compass package also includes some basic information on how to take a bearing and how to follow a bearing.

 

Care Instructions

Suunto says to use mild soap and water to clean the M-3 Global.  I can't imagine a time where my compass would be dirty enough to merit cleaning, but I suppose they have to state something.  More important though are the operating conditions.  Suunto says the compass will operate from -30°C to +60°C, which is -22°F to +140°F.  This is important since the compass is liquid filled.

Speaking of liquid filled, bubbles will form in compasses.  It happens as a result of changes in temperature and pressure, and in general it's not harmful or detrimental to the operation of the compass.  In some cases the sealed enclosure may lose its seal and begin to leak, in this case the compass will slowly fail.  There are some manufacturers that claim that their compasses are "bubble-proof" thanks to some special membrane.  Having not seen or used one of these myself I can't comment.

Above all, just remember to treat your compass kindly.  Be sure not to drop it or expose it to really weird swings in temperature, and it will probably work forever.  Unless you lose it.

 

Warranty

Suunto warrants the M-3 Global against defects in materials or workmanship for the life of the compass.  The life of the compass is defined roughly as until you can't use it any more due to normal wear and tear. Suunto excludes wear and tear, rough handling, modifications, chemical exposure, and misuse, so if you're planning to dunk your compass in acid or throw it off cliffs you should probably not expect the warranty to be honored. 

 

Conclusions & Recommendations

There are lots of compasses out there, and many are much less expensive than this one.  There are also many that cost much more or are much more complicated.  For my purposes, the Suunto M-3 Global is ideal.  It's always in my pack or around my neck, and while I rarely need to use it, it gives me comfort that it's there and will work reliably for many years to come.  As long as I don't lose it like I lost the last one, I'll someday hand this one down to one of my kids.



Happy Navigating!

A Final Note

I did not receive compensation in any form from anyone to write this review.  I purchased my Suunto M-3 Global compass with my own hard-earned money.  The opinions expressed here are mine and mine alone and have not been tainted by any third party.

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