Compass

I have a Suunto MC-2, also a Brunton type 7, made by Silva in Sweden. I use them with the topo, generally as a backup to the gps, and always take a back bearing to the car with them before entering the woods.
 
Dannyboy Leather said:
The lensatic compasses are fine for some applications (like the Cammenga); I used them extensively in the military. However, these are not compasses for orienteering. In fact, for any land navigation that involves a map, I much prefer the baseplate or sighting compasses such as the Silva Ranger (my favorite).
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I also teach a pretty extensive land nav course, and I have to agree with Dannyboy.

Baseplate (or thumb compass if you are going to adventure race) is really the way to go.

Most people that navigate with the Cammenga (or lensatic compass) are doing gross navigation. If you try to perform the same detailed navigation with a lensatic that you do with a baseplate, you are going to seriously complicate your life.

Let me give you an example:

You know where you are at on the map. You see a lake you want to go to. With a baseplate compass you do the following:
- Line the edge of your compass up with where you are at, and where you want to go.
- Spin the capsule until the meridian lines match the north/south lines on your map.
- Done!

Things to take note of this method:
- Orientation of the map is not important.
- Location of magnetic need is not important (you can do this on a metal table or dancing in a circle).
- You are simply using the protractor part of your compass. The magnetic needle only comes in to play when you shoot the bearing to walk it.

Why this is hard with a lensatic:

- Line up the compass edge to your route of travel, and the lensatic wants to give you a number. What does that number mean?
Option A) If you map is oriented north, then your reading is the one you need to travel. However, orienting a map in the field, then trying to spin and move your compass along your line of travel can be difficult. It usually goes like this: Orient map. Go to move compass…..shit! Did the map move? I am not sure, so I better re-orient. Okay, map is good again. Try to move compass along like of travel and spin. Shit….did the map move! Repeat : ) Add on top of that rain, bugs, fatigue, and you get what I mean about this making your life complicated! Also to note that this method relies on the magnetic needle in the compass to give you “the number.” Which means that route planning can be difficult. Set your compass on the table some time and move it around. The needle will go all over the place. It is very HARD to find a table with no metal in it. If you decide to use a small clip board to make orienting the map easier, they have metal clips to beware of. With a baseplate, you are simply using the protractor (not the needle) and do not have this issue.
Option B) Have your number be relative to another number. Don’t orient the map, but find out the reading for the north/south lines on the map. Use math (which I am not a fan of in the field) between that number and your number to determine what bearing you should shoot to get there. Sound complicated? I think so.

Another way around this with the lensatic is to actually carry one of the square map protractors. It will allow you to work more like my description with the baseplate. But, the way I figure is the lensatic is already bigger and heavier than a very nice sighting baseplate, why would I want to bring along another piece of gear to worry about and forget.

Keep in mind, that this was meant to be a simple example, and it is only one. Trust me, the baseplate compass will make your life much easier.

Nothing against the Cammenga. I have one, and they are very nice and rugged as hell. But, it seems that most people that use them are doing “gross” navigation. Such as “I headed in Northwest, and I need to return Southeast." Most are not doing more detailed bearing taking or anything else to realize that it is more complicated than it needs to be.

Also, not to take away from the compass, there is a reason the military uses them. Besides the durability, they can be extremely accurate. They also have a scale on them in mils, which helps in accuracy, but also does make the math easier. Still, I prefer to use no math myself. Just letting you know how they use it there.

A couple other downsides (in my opinion) about the Cammenga are:
- Non declination adjustable. The better baseplates are declination adjustable and can make life so easy!
- Dial is only in 5 degree increments : ( Why have such an accurate sighting compass, and then have guess that much at your bearing? Most baseplate compasses are 2 degree increments, which very accurately lets you split that for 1 degree of accuracy, and without much trouble is very easy to determine bearings to 1/2 of a degree. Much better system IMO.
- Magnfiying glass will not start a fire. It is too weak. I realize that this is not the intention of the glass, but why not have everything multi-purpose.

With all that said....I strongly recommend a baseplate. You have a good one there, so no worries.

One other thing to note, I love the global needles on the Suunto's. Not because I travel the world frequently, but because the separated needle/magnet design is very forgiving for hold angle and also causes the need to dampen super smooth and super fast.

I don't know if I covered stuff as clear as I think I did. So, if you have any questions.....shoot away.

B
 
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Brian Andrews said:
They also have a scale on them in mils, which helps in accuracy, but also does make the math easier. Still, I prefer to use no math myself. Just letting you know how they use it there.
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As an FYI, bearings for mortar and machinegun fire use mils rather than degrees. I imagine artillery also uses mils though I don't have any experience there.
 
j williams said:
cammenga is what I use. Great compass.
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+1 Ive tried a lot of good compasses over the years, but found the liquid filled ones tend to develope bubbles if you leave them in a car with temperature extremes. The cammenga uses a damping system for quick stabelization. I've also found that those 2 dollar pin on ball compasses are handy when rough navigation is all you need. Don't have to canstantly pull out a compass for readings, and no big deal should you forget it's on your shirt and run it through the wash. I
 
BlackHills said:
As an FYI, bearings for mortar and machinegun fire use mils rather than degrees. I imagine artillery also uses mils though I don't have any experience there.
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Yes. Mils is a very accurate system for calling in mortar rounds and such. It also has the added advantage of using the math to do so much easier. Very efficient system. Just too complicated for woods orienteering when there are easier ways.
 
I always have one of my older Swedish made Silva sighting compasses in a vest pocket when out in the woods. :thumbup:

I find it more important then my American Express card, I don’t leave home without it. :rolleyes:




Big Mike

”Scaring the tree huggers.”

Forest & Stream
 
Some people mentioned using the military compasses. They are infamous for sticking and going bad. They're also heavier, much more expensive, the sighting wire is forever getting bent up and they don't come with a mirror or magnifying glass. I've had more than a dozen freeze up on me while in the military and always carried a cheap little Silva model (my first compass as a child) as a back up. As a matter of fact I had my military lensatic compass freeze up while trying to get my Expert Infantry Badge during the long nighttime land nav course while chest deep in a swamp in winter. It was that $10 15 year old Silva that I finished the course with. Wouldn't have gotten my EIB without it, and it has traveled with me to every warzone I've been to and to more than 50 countries.

The only real advantage I see to the military lensatic is the Tritium capsules, which is a nice feature to have. Speaking of which: Hey Storl, would you like to swap your tritium Suunto for a gen-u-wine combat proven $10 Silva? I'll even make up a war story for you and smudge some camo stick on there so it has that authentic feel! We'll call it the Tactical World Traveller Model (note the cool British spelling of "traveler" which makes it more exotic), or some such crap and you can amaze all of your friends with it. Or better yet, I'll buy one of your modified machetes and you can just throw in one of your knives and the Suunto as schwag!

As far as pin on models go, they have a real use in certain situations. I own several of the Silva pin on models that are knock-offs of the Marbles pin on. I keep one pinned onto the shoulder strap of my pack when traveling to foreign cities so that I can can constantly reference direction until I get used to the lay out. I use one pinned to my chest rig during SAR as a quick reference. I use one pinned to a shoulder strap when backpacking on well marked trails as a general reference. I use this model instead of the fish-eye model, because it stays put better with the brass leg on it.
 
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I use a compass often on the job to orient myself at a project site during the initial stages of the project when I may not be totally familiar with my directions. For me part of knowing my way around intuitively is to know my compass directions no matter where I am.

I generally use a small Victorninox Recta(?) that is in a drawer that pulls out or a Brunton 8040G for day to day stuff. At least one is always in my work bag. Both work just fine for me although the Brunton is a lot nicer and has a thermometer and mirror. In the woods, I'd probably have the Brunton with me and a compass works best when you have a topographic map to work from.
 
I carry a Silva Ranger when I know I'm going off trail and I use it to get back to my car. Assuming I'm not going too far out, less than a mile, I can usually get back using the compass without a map. If I'm going on a day hike when not carrying a full on day pack, I use a Suunto Clipper and an REI keychain compass.
 
Ramm9 said:
I've read good things about the "Brunton 54LU" compass but haven't had one in hand yet. Those military lensatic like the Cammenga must be pretty good, they have been around for a long time.
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That Brunton 54LU looks just the same as a Silva 54NL that I've had for 20ish years.

The prism sighting system is terrific - much easier to use than any mirror system. And of course it has all the advantages of a base plate compass.

I need a new baseplate for mine - I broke it a couple of years ago in a fall.
 
I have a compass addiction that's almost as bad as my knife thing. I've got everything from a bubble compass to a Brunton pocket transit. I've found the humble Silva Polaris does most of what I ask of a compass.
 
foxyrick said:
That Brunton 54LU looks just the same as a Silva 54NL that I've had for 20ish years.

The prism sighting system is terrific - much easier to use than any mirror system. And of course it has all the advantages of a base plate compass.

I need a new baseplate for mine - I broke it a couple of years ago in a fall.
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Do you have any problems sighting up or down hill in a mountain environment with the prism style? You write "easier to use," do you think this sighting method is any easier to focus on than using a mirror?

These days I pick a target, look in the mirror for the bearing...blur...put on reading glasses, determine a bearing, look up to find a target...blur...take off reading glasses. Anyone else know what I mean? Helpful hints?



Brian, do your navigation students ever look at you with a blank stare and mutter "huh" under their breaths? ;)
 
The old silva rangers were such a great tool.

Such a shame they changed them

I had one of the new ones and the mirrors fell off (double sided tape) and the fluid leaked out before I even got to use it. Just riding in my pack on a couple of hikes. They also don't have the aluminum bezel like the original. A plastic ring with less accurate markings replaced it.

Carl-
 
I haven't done any orienteering but i may try it soon.
Bought a Silva Ranger (maybe 20) years ago so i guess i'm set.
Have a little Brunton Keychain compass thermometer and a Victorinox compass as well.
I'm glad this thread came up, i have a carabiner compass i was going to use as a backup this summer.
I've been carrying it for a few days on my belt loop, when i first took it out of the box north pointed north.
But today i checked it against my other compasses and everything on it is backwards, North is south and east is west.
How the h*ck did that happen?
 
tholiver said:
But today i checked it against my other compasses and everything on it is backwards, North is south and east is west.
How the h*ck did that happen?
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I keep wanting to suggest you turn around or turn the compass over. Somehow you must have magnetized the opposite side of the needle, maybe by constant rubbing against cloth?
 
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