Alex, maybe it's a matter of semantics to some degree, or a different approach to working with a map and compass in general but I'm not really sure I understand some of the points you've made in your recent posts.

Originally Posted By: Alex
Army issue gear does not imply it's free of flaws. Take any prismatic disk based liquid filled compass and try tilting it a little in various direction, while looking through the eyepiece. You'll see what I mean. Also observe the speed your disk/needle goes back horizontally. It is slow enough to be a bad bubble level substitute, especially if you are in a hurry to make a quick fix at your walking direction.


I brought up the M73 Francis Barker because it's a darn good prismatic compass, and quite typical for its class. It's a mil-spec design but that is totally beyond the point. This is the kind of compass used for precision work in the field, with an excellent track record. Compasses of virtually identical construction have been used by soldiers, explorers and adventurers from Livingston to T.E. Lawrence, so I guess it says something about the longevity of the design.

Not sure where you got that "unreliable expensive prism on a hinge" - the M73 (and pretty much all comparable products) is built like a good old Swiss watch, plus it's plenty sturdy enough for serious field use. Those $5 eBay wonder compasses are not, IME.

The M73 - or any other similar prismatic compass - is capable of very precise measurements as long as the user is vaguely competent in its use. Among other things, this involves holding the compass in a reasonably stable and level position, which I suppose is straight-forward and self-explanatory enough.

I'm not exactly sure what you mean by your previous training or "battlefield surveying tools", but a precision compass is about the most basic tool used for field surveying, and also quite popular in some branches of the armed forces. The Brunton Pocket Transit, the US M2 artillery compass and the British M73 are good examples of their type.

I'd think that anyone trained in land surveying methods of any kind would be well familiar with that sort of equipment and the accuracy it can achieve. BTW, I have never, ever seen any professional mount a compass on a monopod (or a walking stick for that matter). The idea is beyond me, and I can't fathom what one could gain that way. A tripod-mounted surveying compass is a different matter - but now we're getting into a whole new ball game, which really has nothing to do with general land navigation.

Either way, any decent prismatic, lensatic, mirror... even baseplate compass can achieve an accuracy far better than what you stated...

Originally Posted By: Alex
In fact, you can't expect a precision better than 10 degrees. Because anything you can get from a typical baseplate compass will have a comparable error introduced by its very design, dictating a certain overly inaccurate measurement technique.


In skilled hands, a modern baseplate compass can get within +/- 3 degrees (limited generally by the lack of sighting aids rather than any other inherent weakness).

The eBay compass that you seem to hold in high regard falls into a different category, however. If it works well enough to suit your needs, that is fine. But being familiar with that particular product, I would not recommend it to anyone.

I'm not saying everyone needs a "$100 ancient mechanics plastic compass" (??) with the "view obscuring" (uh-oh???) mirror.

I do believe however that anyone serious about outdoor pursuits of any kind should learn at least the basics of map & compass use. Once you master those fundamental skills picking a good compass - one suitable for your specific needs - will be an easy job. Either way, my suggestion would be to look for a quality compass you can rely on instead of wasting your money on inferior no-name products. Land navigation is a pretty serious skill, so there's really no place for worthless gizmos and inferior no-name products.

As always, YMMV smile