UKC

I had a bit of a scare on the Ben Bevis plateau a few days ago. I took a compass bearing from the guide book for the zig zags and found I was pointing the wrong way. As visibility was OK so I disregarded the compass. I have now found the compass has reversed, with North pointing South! Is this sort of reversal common? I did a quick Google and all I could find was stuff about the earth poles flipping. The compass is a Silva so should be good quality.

In reply to Shaw Brown: Strange if you use Dogpile as a search engine it comes up with numerous explanations and warnings.

In reply to Shaw Brown: The other thing is if you take a bar magnet and stroke it with another bar magnet pole to pole, you can reverse its polarity, it sounds like some form of this has happened to your compass.

In reply to Shaw Brown:

I've got two compasses. I always keep one in my rucksac and the other I use for work. Without thinking I put my work one in the rucksack then sometime later found the two were side by side. This has resulted in the polarity for both going haywire and I am in the process of buying a new one on line.

In reply to Trangia: As a sad person I collect compasses and have them on a display shelf, but I always align them in line and have never had a problem. My car compass on the other hand has reversed polarity, but its ok if you know.

In reply to Shaw Brown:

Electronics!!!

Digital camera, GPS device, mobile phone, anything else you can think of that may interfere with them?

Ice axe, screws, crampons, wonder if any of those are magnetised? There used to be a warning that axes could deflect the needle if close in some books, has this been forgotten?

Some ideas for people to think on, and test with their own compasses.

In reply to Shaw Brown:
I remember reading somewhere that historically about every 10,000 years the polarity of the planet reverses. I don't know how quickly this occurs, but if so the must be period of considerable confusion when compasses will be unreliable. With modern electronic navigation I wonder how planes, ships etc would cope?

In reply to Trangia: We are due a flip, there is a lot about it on the web, just put in pole reversal if you are interested.

In reply to Shaw Brown: Same Kind of thing has happened with my Silva Compass, but it seems to follow the 'N' on the twisty dial thing!

Was it new? If so, where did you get it from?

In reply to Al Evans:

I vaguely remembered reversing the polarity of a magnet with another when I was at school. I was surprised that it could happen to a compass with no other magnets around, I must have magnetic ice axes!

I guess I didn't pick up stuff about this on Google because i was flooded with responses about the impending pole flip. I will keep my silva compass for then!

Thanks for all the responses, I hope it will make people cautious about trusting their compass without question.

In reply to Shaw Brown:
15 years ago when I was working in a snowdonia shop we had a batch of Silvas that shwed reverse polarity. I often wondered if it was anything to do with the way they were displayed.

In reply to mattsccm: Took my compass back to Snow and Rock today, the guy said it was to do with the magnet thing in the till and by the doors. He gave us a new one anyway, even though it's possible to fix it with a magnet.