Steel tank affecting compass?

[archer1960]

I did my first dive with my brand new Faber 117 last night, and my wrist-mounted compass seemed to be acting strange when I was trying to use it; it seemed to be about 90 deg off when I was shooting bearings at the surface. I am wondering if the tank might be affecting it, or if I should check the compass itself? By the time the dive was done, it was pitch dark, so I didn't bother at that time.

Anybody seen a steel tank affect their compass?

 

[Doc]

No more so than the steel plate in my skull.

Compasses, at least the old fashioned kind with the magnetic pointer are very reliable. Any number of people have gotten lost by not believing them to be working.

So yes, test the compass while in relation to your steel tank. Being submerged with the insulating properties of water might affect its performance positively. Also keeping it horizontal vs at an up-angle... which you allude to... can help.

Keep it away from your head, though, and beware of any UFOs.

 

[Bob DBF]

Test the compass period. I had one start acting up intermittently, not tracking north properly and acting sluggish. My buddy convinced me it was my skills because a compass does not go bad. It was settled one day after a deep cold dive, as we checked it on shore after the dive, it pointed east and when moved the needle changed at about half the distance the compass was turned. I think the pressure and temperature at depth may have changed the consistency of the oil as it tracked properly the next day in my garage. I got another compass and my navigation improved considerably.



Bob

 

[Jack Hammer]

I've been diving mostly steel tanks, and most those dives were in doubles for about 8 years or more. I've never had an issue with any of them affecting the compass. I have had 2 compasses go bad, they started sticking at depth and gave bad readings. Can't say what's happening in your case

 

[AfterDark]

I've been using steel tanks and compasses since 1968 and I can say unequivocally no, steel tanks will not affect a compass at all, when used as designed. The only compass I've had go bad was the one I dropped a steel tank on!

 

[NAM001]

I don't know if it makes any difference but are you side mounting of back mounting.. It shouldn't make any difference for either. and then is it all steel tanks or just one. perhaps your tank has been polarized or your flash light , computer and or xmitter may be affecting it. ive heard of compasses being affected by the light cord or light being on the same hand.

 

[Kharon]

Being submerged with the insulating properties of water might affect its performance positively.

I'm pretty sure that water, salt water, and solid material (other than iron) have no magnetic insulating properties.

 

[jimbeeler]

I did my first dive with my brand new Faber 117 last night, and my wrist-mounted compass seemed to be acting strange when I was trying to use it; it seemed to be about 90 deg off when I was shooting bearings at the surface. I am wondering if the tank might be affecting it, or if I should check the compass itself? By the time the dive was done, it was pitch dark, so I didn't bother at that time.

Anybody seen a steel tank affect their compass?

I had an analog compass that I had used for years with mixed results. I loaned it to an instructor friend conducting a navigation class and he brought it back to me and told me that it doesn't work right. It didn't seem logical since it's such a simple machine. Some time later I realized that I had attached it to a lanyard with a small metal key ring. After replacing the metal ring with a zip tie, it works great.

Sometimes it doesn't take much metal to throw it off. I'd definitely check it out before depending on it.

Jim

 

[Bob DBF]

Sometimes it doesn't take much metal to throw it off. I'd definitely check it out before depending on it.

I believe it is an inverse square relation, a little metal close will affect it but it takes a lot of metal just a few feet away to have any effect.


Bob

 

[jimbeeler]

I believe it is an inverse square relation, a little metal close will affect it but it takes a lot of metal just a few feet away to have any effect.


Bob

If I remember my physics class correctly, you are correct. It sure did drive me nuts trying to figure out what the hell was going on with my compass. The weird thing is it wasn't pointed to the small metal ring, it was variable. Anyway, I'm doubtful that a steel tank would affect particularly when you are probably holding it out at arms length, it but if a compass starts acting weirdly when diving steel, I'd definitely do some experimentation to find the issue. Is it the compass, the tank or something else.

Jim