I’ve been asked by several readers which compass I use and why I chose it. My primary compass is the Suunto MC-2, my alternate compass is a Suunto A-10 and the compass in my survival kit is a little Brunton Globe. While in the Army we were trained to use the standard military lensatic compass but, during the deployments during GWOT, some SF teams were issued a version of the Suunto MC-2 with special tritium illuminated parts that most of us found to be superior to the lensatic.
Like weapons, not all compasses are of the same caliber and no one compass excels for all uses. Some are toys, some are junk and some are overkill, so depending on the terrain you are operating in and what you are doing at the time, they can get you lost and embarrassed or worse, lost and dead. If I had to bet my life on a compass, it would be either a Suunto, Cammenga or a Brunton. My primary, the MC-2 is considered an advanced nav. compass and it is pretty rugged. My secondary (backup) is an orienteering compass that is quite a bit lighter, and while it won’t take the licks the MC-2 will, it will allow me to continue the mission. The little Brunton Globe is my go-to-hell compass, it will get me home and that’s about all I can ask of it. Avoid very expensive professional compasses designed for surveyors, loggers and geologists. They are usually a little bulky, heavy and you’ll cry like a baby when you lose it or break it. Also avoid the Chi-com made Silva compasses like the plague. Yes, Silvas sold in North America are made in China. The true Silva compasses are still made in Sweden but are not imported here. I still have a Chi-com Silva Ranger someone gave to me that has the direction-of-travel arrow pointing in the wrong direction. The Suunto is made in Finland, the patron nation of orienteering, the Cammenga in Michigan and the Brunton in Wyoming. My only hands-on experience with the Bruntons, beside the little Globe, is the Army M-2 that was used by Army mortar and artillery crews and I remember it being a well-built compass. If you’ve used the virtually indestructible M-1950 military lensatic compass, you’ve probably used a Commenga. The civilian version of the M-1950 is the Commenga 3H. As far as I know, it is the only civilian compass with a tritium illumination. The use of tritium allows the compass to self-illuminate without the aid of a light that is required to charge the phosphorous in other compasses. The life of the tritium is about 10 years (true half-life of 12 years). If you feel that the lensatic compass is for you, a word of warning; there are tons of cheap Chinese knock-offs floating around. I see one or two at each land-nav class I teach. Usually, they are made of plastic, don’t have a dampened floating needle, (the needle never seems to settle down) and the parts that are supposed to be phosphorus are just green paint. Also of note; if you find a military surplus lensatic, it’s probably past the half-life of the tritium and will not illuminate properly. Check for the manufacture date on the back of the compass.
What to look for in a good compass:
The compass should have a liquid filled housing with no bubbles under the lens and a jeweled needle bearing.
The base plate should be transparent in order to view a map through, and have embossed scales relevant to the maps you will use.
The needle, orienting arrow, rotating bezel ring and orienting marks should be luminous for night use.
The bezel should have detents (or “clicks”) to hold it in place when set.
There should be an attaching point for a lanyard. This is pretty important. I usually keep my compass lanyard (a piece of gutted 550 cord) tied through the button-hole in either my top left shirt pocket or lapel, or if no button-hole when wearing a combat shirt, attach it to the suspenders on the battle belt or a plate carrier attachment point. My point is attach it to your person. Do not tie it around your neck, that’s a no-no that might come back to haunt you during a ground combatives engagement. Do not make the lanyard so long that it can reach the ground when you go down on one knee. Old war story; I had a buddy going through SF Selection with me, taking the land nav. exam when he fell onto a knee at night while moving through the woods. His lanyard was so long that when he fell, his knee fell onto his open compass, breaking out the lens and crushing the needle. He had no backup compass and failed the exam. Close your compass cover and stow it away when you’re not looking at it.
Additional items I look for:
A hinged cover with integral mirror. The cover protects the compass face, base plate and mirror from damage and, of course, keeps the mirror from flashing inadvertently. The mirror is used for the more precise land nav. functions such as section/re-section. It can also be used for applying camo, signalling, shaving, and checking for ticks in those places you can’t normally check by yourself and your Ranger Buddy probably won’t help you with. When the mirror is folded out flat, it gives the user a longer straight edge for drawing lines on the map.
Multiple map scales and rules. Something very important to consider before purchasing a compass.
Determine the scale(s) of the maps you intend to use since the scales on the compass need to match them. With the Suunto, the embossed compass scales will either be in inches (standard) with map scales of 1:24,000 and 1:62,500 for use with USGS maps printed for the United States, or for maps of virtually all other areas of the world, the compass scales required will be in centimeters and the map scales of 1:25,000 and 1:50,000. Military Grid Reference System (MGRS) maps, including those of the USA, use metric scales. I keep compasses for both type of maps.
Magnifying glass. Comes in handy for reading the fine map print, especially when you are long-in-the-tooth, like me, and the eyes start to go bad. It can also be used to start a survival fire, providing the big heat-tab-in-the-sky is shining.
An adjustable declination setting. Determine the declination for your AO, set it into the compass once, and forget it. Big time saver and one less mistake to make.
Sighting apertures and wires between the base and hinged lid.
Most compasses are hemisphere specific. A compass made for the northern hemisphere will not work in the southern hemisphere and vice-versa. You can, however, buy a special compass that will work in both.
For example: The Suunto MC-2 360/D/L/CM/IN/NH has/built-n Declination adjustment/Luminous dial/inClinometer/INch scale/works in the Northern Hemisphere. The Suunto version for both north and south hemisphere will have the letters NH/SH or G for Global. Each uses a different method of needle stabilization.
If you have any interest in land navigation and are planning a compass purchase, visit your local sporting goods/backpacking store and puts your hands on one first. Usually someone behind the counter will have some experience with one. Another good source of information is a local orienteering/hiking club.
I have updated this post to include this Youtube video that I think will help. It is very well done.