Beware Mobile phones and compass!

I was out activating GM/NS-025 Beinn Enaiglair - 889m a couple of weeks ago. True winter conditions, snowing on the summit with poor visibility. Got the summit activated, now to navigating off… The compass said we should go in the opposite direction to where intuition said we should go… Moira, said I should check the GPS. I said compasses never lie and you must trust it even if it seems wrong, this has worked for me many times in the past… I got the GPS out and it said the compass was 180 degrees out… comfirmed with Moiras compass. My compass had been sitting in the top pocket of my rucksack with my Blackberry molile phone in it’s magnetic case. The compass had been re-polarised 180deg out! Have often had phone and compass in the same pocket. Never had a problem before. Will never keep them in the same pocket again!!!
So I thought I should warn you all of this possibility. SILVA have kindly repolarised my compass and said this can happen with mobile phones of any make and and GPS’s.
If Moira had not been on the ball we could have walked off the wrong side of the hill in poor visibility into who knows what, we were expecting an easy slope, we may have happened on a cliff. When you have been playing radio on the summit you can get disorientated and may not realsie there is a problem. So from now on mobiles and GPS units will be in a different pocket to the compass!

Has anyone else experienced this problem?



In reply to MM0DHY:

I had hung my old (1970’s) Silva compass by the string from a metal tool board. When I took it down to use it I found it too was 180 out. I used it like that for ages before the slightly brown plastic cracked due to aging and lost the fluid in about 2007. I was a bit shocked to see how much a new one was 30 plus years later.

Steve GW7AAV

In reply to GW7AAV:

In reply to MM0DHY:


I was a bit shocked to
see how much a new one was 30 plus years later.

Interestingly enough Steve, last summer, G1STQ showed me his new compass which he had just purchased for a tenner from one of the camping shop chains. I showed him mine, that I picked up from Poundland, for …err, a Pound.

They were identical!

For the sake of 2 quid, I went back and picked up a couple of spares.


In reply to MM0DHY:
Agh ,the Blackberry magnetic leather wallet. It should come with a warning label! I wiped two rail season tickets before I found what was erasing them.

In reply to MM0DHY:
I was just reading through this months Trail magazine, they have a short article about this very subject

“Keeping your compass close to your mobile or car door speakers can cause problems, the speaker in your mobile contain a minute magnetic induction coil which effecitvley ‘strokes’ the ferromagnetic material of your compasses needle and hence can reverse its polarity.”


In reply to MM0DHY:

Been there, done it - The incident is known in my family as “The day God moved the Cairngorms”! Now I carry two compasses, one in my pocket one in my pack just in case

Barry GM4TOE

In reply to 2E0YYY:

I have had a couple of cheap compasses although not from Poundland and I decided to get a new Silva because the others were rubbish. Helen has one from Asda that she bought as part of a pack, she only really wanted the map pocket, it works okay if you get it completely flat. Other cheap ones I had either leaked or had no fluid inside and stuck most of the time so you had to give them a tap.

I think I paid £30 for my present Silva but it had been on sale at £49. I hate to think how much they are now.

Steve GW7AAV

In reply to MM0DHY:

I have a cheap compass well wrapped up in my rucsac for emergency use. The tradition is a cut open tennis ball or a piece of bicycle inner tube as the wrapping but I use a bit of bubble-wrap held together with masking tape…mind you, I was lucky to get the bubble wrap, my XYL can’t resist popping the stuff!


Brian G8ADD

In reply to G8ADD:

To tell the truth, I’m a bit amazed. My son works weekends at Poundland, so I asked him to look for and get one of their compasses. It looks like the real thing, but it is undamped. Perfectly useable and I think better than my present emergency compass so I am wrapping it up safely and putting it in my gear. A good buy, in my opinion, and less tatty than many of their “bargains”!


Brian G8ADD

I have a number of compasses of various degrees of expense - and all of them get used from time to time.

I have (owned for a long time) a (Recta branded) compass that I bought in a hiking shop.

A year or two ago Aldi were selling, as one of their special WIGIG (When It’s Gone It’s Gone) offers, a rather nice set of yachting binoculars with a built-in compass in the right ocular.

Because I have a slightly dicky ankle, my wife bought me a collapsible walking stick (with trekking shock absorber system), and there is a really cheap compass built into the wrist strap. This one is good enough to say “that’s sort of North-ish”, but not more.

I used to own a wristwatch with a built-in flux gate compass, but it died.

I also know how to find North by looking at which side of the Boy Scout’s wristwatch the sun is shining on, or which side of the Boy Scout the moss is growing on.

In reply to G6ENU:

I too have a variety of compasses that I have collected over the years, from a vintage Silva (my first bought when I was just 17) to the whizz bang electronic one in my GPS.

The venerable antique suffered a reversal of polarity on Y Golfa a couple of years ago. Wierd thing is (cue spooky music) I was well aware of the issues of magnets affecting compasses and always kept mine remote from microphones, headphones and similar injurious items…

Since then I have always carried two compasses, and a boy scout as backup so I know which one is telling the truth…

73 de Paul G4MD