Go Back  The Hull Truth - Boating and Fishing Forum > BOATING FORUMS > Marine Electronics Forum
Reload this Page >

Installing a new compass - Is it as easy as...

Notices

Installing a new compass - Is it as easy as...

Old 12-12-2003, 12:19 PM
  #1  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Jul 2003
Location: St. Pete FL
Posts: 262
Default Installing a new compass - Is it as easy as...

pull the old one out and drop the new one in? Or do I have to worry about magnetic deviation or some such anomalies that require professional help?

St. Pete Bob
St. Pete Bob is offline  
Old 12-12-2003, 12:24 PM
  #2  
Senior MemberCaptains Club Member
 
Join Date: Feb 2001
Location: West Virginia
Posts: 3,877
Default Installing a new compass - Is it as easy as...

I am not going to answer this question, at least not now. I want to see the sage advice from all those guys who posted on that other compass question that you can not be without one because its the only thing on this green earth that you can rely on. Let's see how many of them can give you an answer without plagerizing Chapman's.

Thom
Thom is offline  
Old 12-12-2003, 12:35 PM
  #3  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Jul 2003
Location: St. Pete FL
Posts: 262
Default Installing a new compass - Is it as easy as...

Sorry if there was another recent post on this that I missed. It's just that my compass which sits on top of my Furuno 1833 is off five degrees or so from what the Furuno says. The dude that installed it said something about having to contact a compass guru to "tweak" the compass to agree with the GPS. Come to think of it, how do I know the GPS is not off the five degrees - I assume they should match right?

Didn't touch off another fire storm did I?

St. Pete Bob
St. Pete Bob is offline  
Old 12-12-2003, 12:49 PM
  #4  
Senior MemberCaptains Club Member
 
Join Date: Feb 2001
Location: West Virginia
Posts: 3,877
Default Installing a new compass - Is it as easy as...

Shoot me an E-Mail
Thom is offline  
Old 12-12-2003, 01:11 PM
  #5  
Senior MemberCaptains Club Member Admiral's Club Member
THT sponsor
 
Join Date: May 2002
Location: Brookhaven, LI, NY
Posts: 15,755
Default Installing a new compass - Is it as easy as...

Simply drop it in, then get out a chart of your area and find something you can track easily (light house, water tank...) that's marked on the chart. Now go out on the water, point the boat at that object and stay on it's course driving slowly (5 mph), check what the heading on the GPS says. Compare that to what the chart says it should be, they will and should match perfetly. Make sure the GPS is set to TRUE heading not magnetic.

Now, adjust the compass by turning the adjustment screw until it also reads the same heading.

Lastly, do this a couple times heading at different directions and adjust so It is as close as possible. You may find that heading North it will match perfectly, but heading East it is off 2 degrees. If you then adjust the compass so East is right, the North will then be off 2 degree's... Don't worry about it, it's not a rocket science as most folks will try to lead you to beleive.

Wind, current and everything else will throw you off coarse more than that 2 degrees variation most of the time anyway. And to top it off, I haven't used a compass in A LONG time. Yes, I look at it and check my headings... but what I mean is, I have not NEEDED the compass and probably never will.



Birdman, Capt of

Scout Abaco 280 Click here!
Birdman is offline  
Old 12-12-2003, 02:39 PM
  #6  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Jul 2003
Location: St. Pete FL
Posts: 262
Default Installing a new compass - Is it as easy as...

Birdi - thank you for the "how to" info. Funny, I don't know if I still have a paper chart since the plotter came aboard! Better start digging, should have one anyway I guess.

St. Pete Bob
St. Pete Bob is offline  
Old 12-12-2003, 04:14 PM
  #7  
Senior MemberCaptains Club MemberPLEDGER
 
Join Date: Feb 2003
Location: Thornton's Ferry,NH,USA
Posts: 10,631
Default Installing a new compass - Is it as easy as...

As Birdman pointed out, you want your GPS set to 'true' north. Your local 'variation' for 'magentic' north may be the only reason your 2 instruments dont match up.

Also, your boat and gear may cause another error called 'deviation.' If the error has been constant after you calculate for 'variation' this is the likely culprit. You should expect a similiar behavior for any magnetic compass you install.

If this difference is constant then it really isnt considerred a defect since you can compensate for it by steering a corrected course.

Good luck!
Kamper is offline  
Old 12-12-2003, 04:16 PM
  #8  
Senior MemberCaptains Club MemberPLEDGER
 
Join Date: Oct 2002
Location: mass/Point Judith, RI dockage
Posts: 11,146
Default Installing a new compass - Is it as easy as...

Now, Now Thom. Why so down on that "other" topic? btw, I don't think any actually said they couldn't rely on anything else, just that the compass was the easiest reference point in _certain_ conditions. And yes, I know how to display a real time reading on the display of my plotter (I find the compass easier to read). My real point was don't use the chart display with the little boatie to steer by if you have a compass........

btw, unless I misread birdies post it looks like you will end up with your compass adjusted to True north, not magnetic. Thats not a big deal, but it can throw you off if you go someplace with a different variation (or is it deviation, I never keep those straight). It may not matter to you though if you don't use it for navigation over distance.

To get it to magnetic, just add one more step of using the variation from the compass rose
to set the compass to mag north for that location.

** yeahah **
gerg is offline  
Old 12-13-2003, 01:57 PM
  #9  
Senior MemberCaptains Club Member Admiral's Club Member
THT sponsor
 
Join Date: May 2002
Location: Brookhaven, LI, NY
Posts: 15,755
Default Installing a new compass - Is it as easy as...

quote:Originally posted by St. Pete Bob:
Birdi - thank you for the "how to" info. Funny, I don't know if I still have a paper chart since the plotter came aboard! Better start digging, should have one anyway I guess.

St. Pete Bob

Bob,
If you NEVER listen to a thing I ever say, or ever will say, that's fine. BUT, PLEASE listen to this at least: GET A PAPER CHART OF YOUR AREA. There is NO substitute for carrying a good old fashioned paper chart for when all else fails. If nothing else, it's nice to reference/study a paper chart at home or the dock prior to making a trip. You'll understand where and what your piloting thought much better if you study it on paper first.

Good luck.

Birdman, Capt of

Scout Abaco 280 Click here!
Birdman is offline  
Old 12-13-2003, 05:40 PM
  #10  
Senior MemberCaptains Club Member
 
Join Date: Apr 2001
Location: Northern California
Posts: 277
Default Installing a new compass - Is it as easy as...

If you don't want to worry about calibrating a new compass,do what I did.Drop a KVH digital 1000 in the boat,hook up 12 volt power and make a wide slow 360 degree turn with the boat.That will compensate all the magnetic interference out and be accurate to 1 degree.These can be found for a good price on Ebay!!


quote:Originally posted by St. Pete Bob:
pull the old one out and drop the new one in? Or do I have to worry about magnetic deviation or some such anomalies that require professional help?

St. Pete Bob

JOHN
SPORT-CRAFT 252
john sturdivant is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread