Bushwalk Australia

I've been browsing the net for info on compasses as I intend to buy one and came across terms like "global needles". I found out that compasses needs to be balanced to specific regions to work properly. As I was likely to buy from os this could be a problem as ,I assume, most are balanced for regions in the northern hemisphere.

Are the ones you buy here identical to the northern hemisphere ones or are they specific aussie compasses (region 5) with identical model name?

Has anyone had any issues with non-aussie compasses here?

Is it neccessary to get a global needle?

Link about global needles
http://www.thecompassstore.com/whatisglobne.html

Can't find anything on Silvas site about this but Suunto has one with a global needle
http://www.suunto.com/global/en/product ... -global-cm

Any thoughts?

Most regular brands of compasses (Silva, Suunto etc) make compasses with needles appropriately balanced for specific zones of the world. If you turn your compass upside down and look in the centre of the round compass vial you should see "MS" and possibly two numbers which appears to be the year of manufacture. "MS" is the norm for use in Australia while "MN" is the standard in the Northern hemisphere. I haven't looked at this for some time but Silva used to make compasses for 5 separate zones; I think the codes were MN, N, E (for equatorial), S, MS. Every now and then a compass with the wrong vial makes it to Australia and shops get a complaint about "my compass doesn't work". I have actually seen one being used in the field by someone who didn't know how a compass should behave.

The take away of this message is be careful if ordering a compass from elsewhere in the world. Or the corollary of buying a compass here to use overseas.

The compasses sold here are identical to the OS ones apart from the round needle vial. There is usually no marking on the outside packaging to tell you which zone either!

i bought a compass from the USA without knowing about this..... and yep, it does exist.

the compass still works ok, but what it means is that the needle will 'scrape' on the bottom if you hold the compass flat. if you tilt the compass a little so the needle can balance then it seems to work ok. it hasn't really had too much of an impact on me, but then i've never had to rely on this compass. if i was buying one again i'd buy one locally, unless it was something like 80% cheaper to buy it overseas or you weren't relying on the compass for your safety.

funny the things you learn ay!

It's all true.

Just buy the compass you need in the place you need it.

This matter has been discussed extensively in previous posts.

Try here ..

viewtopic.php?f=15&t=6407&p=78548&hilit=compass+zones#p78548

and here ..

viewtopic.php?f=15&t=4798&p=57192&hilit=compass+zones#p57192

and here..

viewtopic.php?f=15&t=1258&p=9799&hilit=compass+zones#p9799

rucksack

So, after actually reading those linked threads more carefully (thanks for the links, I should have known the answers were close at hand) it seems some find it to be a problem but others don't.
A global compass looks like a good idea so you never have to worry about it.

If a global compass is such a great idea then why doesn't Suunto fit all of their compasses with this technology? There must be some tradeoff in terms of weight, cost, response or accuracy. What is it?

Orion wrote:If a global compass is such a great idea then why doesn't Suunto fit all of their compasses with this technology? There must be some tradeoff in terms of weight, cost, response or accuracy. What is it?

Good point.
Weight and cost doesn't seem to be tradeoffs. The suunto I linked to weigh 44g and can be had for less than $50 (US). Not sure how much it is here.
Response? I read somewhere that it is actually easier to use as it responds better to uneven handling ie not so sensitive to how flat you hold it. Don't know if this is correct.
Accuracy? No idea. Anyone?

I've not seen one, but I suspect the best way to get around the problem would be to make the needle chamber deeper. That would also have the side benefit of making the compass more flexible to tilting, but it probably means more bulk. ?

I bought a Silva here and in the UK. I can't remember, but I doubt I paid more than $50 total...

First, if you buy a "normal" compass you definitely need one for zone 5. I've got one of the Suunto sighting compasses with the global needle and it certainly seems less sensitive to how you hold it, which makes sense given it's no longer susceptible to dip (though it still has a levelling bubble). I think the major trade-off is cost. It's hard to compare exact models but looking here in Oz a standard field compass goes for $25-30 whereas the global version around $75-80.

Only other thing I can say is it works - haven't got lost (yet)

Cheers, Andy

I have a Silva Voyager 8010 compass, which can be used anywhere, plus a Silva Type 54 Sighting compass, balanced for Australia and a Suunto GPS Plotter, also balanced for Australia. The Type 54 is the heaviest at 70g, the Silva Voyager 8010 the lightest at 36g. The Suunto weighs in at 70g. The difference in weight is essentially attributable to the varying sizes of their base plates, (all three are base plate compasses). The actual compass housing on the internationally balanced Silva Voyager 8010 is the smallest of the three compasses, but the Type 54 also includes a sighting mechanism and the bezel on the Suunto GPS Plotter is much larger than the other two. In use, the Silva Voyager 8010 settles very quickly, and perhaps more quickly than the other two, but I don't think by very much. Whilst Silva and Suunto each have globally-balanced compasses in their line-up, they offer a much larger range of compasses zoned for individual parts of the world. I am assuming that it comes down to sales; that is, fewer people buy globally balanced compasses. I haven't come across any literature which states that one is more or less accurate than the other, but I am sure that I have read somewhere that the globally balanced compasses tend to settle more quickly. If true, that may have to do with their construction, which differs slightly from the more common 'zoned' compasses. My experience is that the settling on my Voyager 8010 is faster, but only slightly. I bought my Voyager 8010 in Cardiff. It cost less than my other two compasses, and in the case of my Type 54, a lot less. Put all this together and one could probably deduce a few things, but I will leave that to others to mull over. I bought the 8010 for walking in Asia, but I have also used it in Tasmania. It works well in both environments. If I was only walking in one global zone, I suspect that I would likely just buy a compass balanced for that zone, as the choices are far wider. With Silva and Suunto's globally balanced compasses, each essentially only offers one model, and then a couple of variations on that model. It's a personal choice.

rucksack

Sorry Andy, I composed my reply before I saw yours. I am probably not comparing apples with apples; a Silva Type 54 Sighting compass is not the same as a 'regular' Silva base plate compass, but from memory, I don't think the price of my Voyager 8010 was all that different from an equivalent single zone Silva compass. I could be wrong about that, of course, but Australian prices are often at one end of the retail scale, as posts here often comment. The other thing, is that I don't often see these globally balanced compasses in the outdoor shops, another reason to think that demand for them is not so large - but they work and they do save thinking about zones!

rucksack

Hi

First struck it with a compass that I brought in Europe and found it did not work well in Australia. It was a cheap one so no great loss. The USA Army ones have a deep well so operate anywhere on the globe. Also use induction damping so are quicker the steady. Trouble is the graduations are optimized for artillery fire rather than direction finding. No great issue but still an annoyance. I use world ones now and not any issues so assuming that you are not being charged and arm an leg might as well go for a compass that works anywhere. I think the trick is how the needle is magnetized. Doing in a particular way means that the the "dip" in the needle is controlled.

Cheers.