Compass Deviation Issue

[Bob DBF]

Musta been some underwater anomaly that messed it up

My buddy's compass worked flawlessly, as has my new compass along the same line. There is something with cold and pressure that makes it sluggish and hang up somewhere other than north.

Some day when I have nothing to do, I'll take it back out with my other compass for more data.


Bob

 

[Anthony Jones]

Cheers - M²[/QUOTE]

I keep both compass and comp on my left hand but on the opposite sides of my wrist: comp on the inside, compass on the outside. Works OK (my comp uses a quarter-size lithium 2322 battery.

Was the digital compass affected by the magnet on the magnetic compass?

 

[tarponchik]

It would be interesting to check the heading when it is on your computer wrist against the heading on the other wrist. My guess is that it will be a little different. If you are using your compass for out and in, it shouldn't make much difference because the induced deviation will be the same both ways. But what do I know?

Cheers - M²

I just checked. The needle deviated about 5 degrees when I touched the compass with the comp on the side, but there is no effect when the two devices are on the opposite sides of my wrist.

 

[MargaritaMike]

I just checked. The needle deviated about 5 degrees when I touched the compass with the comp on the side, but there is no effect when the two devices are on the opposite sides of my wrist.

Great! I would have guessed a different outcome, but I'm glad that you are now aware of what the effects CAN be.

Cheers - M²

 

[tarponchik]

Great! I would have guessed a different outcome, but I'm glad that you are now aware of what the effects CAN be.

Cheers - M²

Like, what? The compass CAN blow up and my hand CAN get severely burned?!

 

[Bert van den Berg]

Thanks for your post. Normally the compass is on my right wrist with the dive computer on the left wrist. The last four dives we were hunting lobsters so I put the compass right next to my dive computer on the left wrist. Never thought about the computer causing compass deviation. Thanks to you I'll check it out next time.

 

[The Chairman]

Normally the compass is on my right wrist with the dive computer on the left wrist.

As an aside, using a compass on the wrist can be problematic. The lubber, or idiot line, is the imaginary line that runs through the center of a vessel. In this case the "vessel" is the diver. Getting the compass to bisect the diver and remain level while on the wrist can be nigh to impossible for some. Using a clip on compass, that you hold with the hand or taking the compass off your wrist and holding it with your hand allows you to sight in and level the compass more easily. In addition, that 6 inches from your PDC will render the influence to mostly nill. Many divers improve their compass skills just by doing this one thing.

THE IDIOT LINE HAS TO ALIGN WITH THE CENTER OF THE IDIOT FOR YOUR COMPASS TO BE ACCURATE!​

For those who wonder why I call it the idiot line, look up 'lubber' in the dictionary. There's some history there that's pretty cool as to why it's called that. It'll make you chuckle the next time you use it.