Weird compass readings

[BBL-Butt]

This is really weird I have a Mares basic mission compact console, well I noticed on my last dive on the coast(where you really need to know where you at) my compass was reading backward from my buddy's. So when I came home I pulled the compass from the console to check it with another compass I had around the house and guess what read fine I went to put it back behind the pressure gauge and boom North was now South and vise a versa?????? what could of caused that I wonder has this happened to anyone else out there?

Thanks
B

 

[diveprof]

Do you have a knife mounted to the back of your console, or some other metal object on the console? Metal can make a compass screwy. When working with students, I show them how the compass reads in the back of my SUV (the metal makes North read South) to make this point.

 

[Marek K]

You're sure you're not looking at the side-read numbers, which are 180 degrees off from the N-S-E-W markings? That's so you can read the heading in the direction you're pointing when you read the compass from the side.

 

[BBL-Butt]

Thanks Dive and Marek, I think some how my metal thumb dial you use to mark a max depth may of been magnetized some how,Because when I took the compass out to check it with the other they just read the same ....then when I tried to re install the compass N&S swapped sides.I'm looking to see how to demagnetize something on the web.......I'll try my other compass on the console to see if I get the same reading ........no metal near it??????

 

[BBL-Butt]

Ok I checked the metal thumb dial and I put my other compass to it and Bingo happened again.....now how to reverse it

 

[noreastDIVER84]

I have found that at one of my dive sites there is an underwater electric cable and it causes havoc with my compass.

 

[BBL-Butt]

Well since it's a mechanical type pressure gauge,I'm going to try a demagnetizer like the ones you use for erasing video tapes and try to fix it that way,the only thing I can think that did it could be it hit on my steel tank hard and the metal on metal created the magnetization..........crazy I mean what do I do get a new console? I guess I could wear the compass on my air hose but would the rubber diagram on the back of the gauge need to have the plastic from the compass to keep it working????If I can fix it I'm giving the gauge needle button a dot of barge cement.......