Deviant Behavior....

[Warren Milberg]

I had been using a foam clip-on holder to mount my air horn on the pedestal of my boat, just forward of the binnacle. Without realizing it until recently, I noticed that that my ship's compass was off by many degrees when running a known course. At first, I thought that I just needed to swing the compass again. It was then that I realized the air horn's canister was probably ferous metal and causing the problem. When I moved the horn away from the binnacle, the compass righted itself.... You, too, may want to check for any metallic objects near your compass that could cause it to be off by many degrees....

 

[Ross]

One helmsman laid his pocket knife on the ledge of the binnacle and had the same problem.

 

[cephius (Dave)]

Different horn

Put one of these next to your compass, no worries.

http://www.everhartmarine.com/eshop...product_600142.ATTWOOD_BELLOW_SIGNAL_HORN.htm

It takes very little blowing to make a big noise and you never need to change the canister. Doesn't rust out either.

 

[duality]

when i was learning to sail many years ago at the lido sail club in newport beach, the instructor was telling a story about a member who used the pedestal to hold his boom box radio on a trip back from catalina. 12 hours later without any sight of land it was detemained that he was south of san diego on his way to mexico. could be folk lore but ill never forget the story and have kept metal away from the compass!

 

[Ken13559]

i was taking fixes within those small compass you line up with you eye and the target. its was 167 deg all the time. found out my spectacles with small magnet pieces each side for clip shades is causing the problem.

 

[BobM]

Watch out for cell phones too.

 

[jibes138]

Mounted a compass on my brother's Robalo center console, it was all over the place. Turns out the steering wheel was magnetic and effecting the compass. Also mounting a VHF radio near it, the radio has a speaker and all speakers have magnets. I'd guess a handheld radio and even a GPS if it has a small warning beaper might be a problem.

 

[svmaja]

portable phones or thier bases.