Compass deviation

[JD-MDR]

My new sr-2 is about 40 degrees off. I found out the instrument panel,wires are throwing it off .Thanks John for the advice. Richie rep told me about a product g-iron. It's like a foil that I can put around the back of my instrument panel (or compass, ,I guess)to stop the interference. I hope it works .I really want to keep the compass at that location. Am looking for g-iron .

[John Stone]

Well, I have to say, if you expect your compass to be accurate ... and if you desire to have a high degree of confidence in it ... I don’t think that is a very good location. There is just too many potential issues associate with such a location to have confidence in a compass that could be affected by electric currents as well as by all the metal in that instrument panel. And that does not even include the hardware located around it.

There is no end to the options as availible to us as we work on our boats and try to make them best meet our needs, but some options are better than others.

Chose wisely.

[JD-MDR]

It would be nice to keep the compass on the bulkhead. The other side has the batteries and switch and breaker panel.What do you think about putting it on the forward side of the wood steering housing directly under the wheel for the steering or do you have any suggestions? I really want my compass accurate. Its more fun to be simple and old fashion and I can't afford all the modern electronics yet. Maybe I should exchange it for a bracket mount type.

[Jim Davis]

Seeing that you have a ketch try it on the mizzen. That should be about as far from error producing things as possible and still convient to the helmsman.

[John Stone]

I actually think the aft end of the cabin top—right where you have it— is a perfect place for a bulkhead mounted compass. It’s where I installed the compass on the Far Reach and I am very happy with the location. I attached a picture. But it’s the only thing there. I was very careful during the rebuild to make sure there was minimal chance for magnetic deviation due to magnetic interference.

I would think there is all kind of steel in that worm gear steering on your boat that would affect your compass. The aft end of the mizzenmast as suggested by Jim Davis might work. Or on a bracket on the top of the vertical face of the cockpit footwell.

Personally, I’d consider moving all that stuff on the aft end of the cabin top so your compass can be there without interference. All that other stuff can go lots of places to include below deck which, IMO, is the best place for it. Others will disagree of course. Your compass should have priority as you need to be able to see It when you are steering the boat, and preferably on any point of sail.

It’s a lot of work to move that stuff and then fill in the holes, fair it smooth, and paint. But it’s doable. And, I understand if it’s just too much work especially if this is not a boat you plan to keep. All reasonable and worthy considerations.

[JD-MDR]

Your right John, I want it on the bulkhead. I think the brackets on the mizzen or on the sides of the cockpit will get banged too much. I do plan to keep this boat for the rest of my time here ,hopefully 20 -30 yrs. Its my fifth boat and is what I want . Maybe I can just move the ignition panel and get rid of the knot meter . Any way I can't do it now. But I need a compass now. I could mount it on a hollowed out block of wood on the cockpit side close to the mizzen. That would be right on top of the engine? I may just dive in and move those electronics etc. I wanted to sail this weekend. Will the compass be damaged by leaving it there for a while?

[John Stone]

JD
There are all kinds of temporary options you can make work. I do all my costal navigation with a “hockey puck” style hand held compass. It works pretty well. You can mount a compass to a bracket anywhere you want as long as it works. And let’s be clear. You should “swing” (make a compass deviation card) any compass as almost all compasses will be affected by the significant metal on a boat. You just need to know how much on the different compass points so you can incorporate the deviation when you determine your heading.

All those holes can be filled so perfectly you can’t even tell they were ever there. Here is a link to some before/after pictures. In the second row of pictures is the aft end of the cabin top. Also note the huge hole in the forward starboard cockpit well where the engine instrument panel was located. All those holes were filled in.

http://www.farreachvoyages.com/beforeafter.html

Here is a link to some techniques you can use to fill those holes if you decide to relocate some of the instruments.

http://www.farreachvoyages.com/projects ... erior.html

[John Stone]

Reguarding damage to the compass, I don’t know the answer to that question. I wouldn’t think so but that’s just a guess. Magnetism is a funny thing. You might call Richie and ask them. They have a tech branch. I called them before I installed my own compass as I wanted to better understand compass “dip” if I ever sail across the equator. They were very helpful.

[JD-MDR]

Ritchie has been great. They were the ones where recommended g-iron.Did you read the earlier post? It's a foil type product that blocks all magnitism . I found a website in Italy If it's not too expensive I might try it.

[Jim Walsh]

Ritchie has been great. They were the ones where recommended g-iron.Did you read the earlier post? It's a foil type product that blocks all magnitism . I found a website in Italy If it's not too expensive I might try it.

The mention of this product made me curious so I googled it. It is available in the USA, I found it listed on Amazon. This product seems to have very mixed reviews. Caveat emptor.......

[JD-MDR]

And not cheap. I will plan on moving the instruments.

[mgphl52]

And not cheap. I will plan on moving the instruments.

I believe that will be your best solution. KAYLA came with compass on the port side & instruments to starboard and I have never had issues...
BTW, her battery switch and breaker panel are also on the starboard side.

[Neil Gordon]

By the way, wherever you mount your compass, check for deviation with electronics both on and off, and best in various combinations.

[JD-MDR]

I sure am getting lots of help. Thank you all. I'm going to the boat in about an hour. I will start removing the ignition panel a hopefully I can stretch the wires away to a better place.

[Bob Ohler]

On a CD30 ketch, obviously your mounting options are limited. Hopefully you can make the bulkhead mount work.

Fair winds.