compass

blstriker

Cadet
Joined
Oct 30, 2004
Messages
10
I have a Ritchie compass that may be either damaged or just needs to be reset. I tried pulling it apart but couldn't get it out of the dash. The boat was from the east coast and I am on the west coast. How do I reset it/ calibrate it/ whatever. How do I know if it works. Do I need to replace anything?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: compass

The compass doesn't care if its on the east or west coast. :) As for knowing if it works, point it north. If the compass agrees, it must be working. If not, there are X-Y axis adjusting screws somewhere on the housing. You can also use another known good compass and compare yours with the good one. If its working, leave it in the dash. If not, getting it out of the dash should only consist of removing the U-bracket, disconnect the light wire (if there is one) and pull it out.
 

Boatist

Rear Admiral
Joined
Apr 22, 2002
Messages
4,552
Re: compass

Strikers<br />Welcome to the board. What makes you think it is not working right. Compass reads magnetic north not true north. Normaly the compass when you get it will be adjusted perfectly. When you mount it on a boat there will often be things that affect the reading. To compensate there are two adjustments. A North/South and A East/West.<br /><br />To adjust on the boat must find a place where you know exact magnetic North. Then you can swing the compass and adjust. Better if you do it off the trailer and away from you Vehicle. Fallow the direction closely. Make sure your only turn North /South screw when boat is pointed MAGNETIC NORTH OR MAGNETIC SOUTH. Only turn the East/West screw when the boat is Pointed East or West.<br /><br />If you do not have a dock or something that is lined up to magnetic north it better to adjust nothing. Some charts will have two Buoys that are lined for magnetic north that you can use.<br /><br />In large body or water a accurate compass is an important saftey iteam.
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: compass

strikers, there's are a couple of things that effect a compass. 1 is devation. which boatist is talking about. any eletcrical items, any metal, next to yer compass will effect it. (i mean even the zipper in yer pants might effect it if yer zipper is close enough to the compass, let alone a windshield wiper or something like that)the compass on yer boat may need to be adj. for that. i've never done it but there is what's called a devation table. devation will be different for different headings also. it's for your specific boat, your specific location of yer compass on board. the other thing that effects it is variation. this is different from one location to the next. it is the difference between magnetic north and true north. charts will have this varition printed on them, and charts are printed true north, yer boat is on a magnetic corse. on the east coast the varition will be west. if on the west coast, varition will be east. man, there's alot to be learned about a compass. yer compass may be alright as is. try compensateing for variation for where yer at. the chart i'm useing to learn this has 015* west varition. that means that when my compass reads 015*, i am really going true north. or 000*. you can also compare yer boats compass to a gps. be sure the gps is in the magnetic north mode. the gps will not account for varaition i don't believe. but is uneffected by deviation. as it get's it's info from satalites. this statement is to the best of my limited knowledge, and is over simplified. any of you real navagators out there feel free to correct me. i'm still learning too. :)
 

blstriker

Cadet
Joined
Oct 30, 2004
Messages
10
Re: compass

thank you to Boatist and Ziggstardust. Both of your replies were very helpful. This forum is a great resource.
 
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