Deviation card /table?

jackdale · #1 (**permalink**) 01-26-2009

How many of you have a deviation card / table on your boat? I have sailed about 40 different boats. Four had deviation cards / tables. Yes, many of them had deviates on board too. ( I had to get that in first)

Jack

AdamLein · #2 (**permalink**) 01-26-2009

In a binder with all sorts of documentation that came with the boat, I found an almost-totally-faded deviation card. I can't read some of the values. I've never sailed anywhere that I couldn't see where I was going, so even though we use the compass, we don't depend on it. When I wasn't sure, the GPS told me... some day I'll get around to making my own deviation card.

Also don't compasses usually have weak internal magnets that are placed to cancel out the deviation?

jackdale · #3 (**permalink**) 01-26-2009

Quote:

Originally Posted by AdamLein

Also don't compasses usually have weak internal magnets that are placed to cancel out the deviation?

The adjustment magnets can account for SOME deviation. After a compass compensator removes as much deviation as possible, they can then create the card.

Jack

jrd22 · #4 (**permalink**) 01-27-2009

We had the compasses done and cards made on the last boat, haven't done the new boat yet, but will in near future. The compass is so much easier to use to steer a course when it's rough than a chartplotter.

Bene505 · #5 (**permalink**) 01-27-2009

Flying we always had one. In a plane it's easy. You go to a runway that has special marks on the pavement in the shape of a circle. You taxi the plane into the circle at different angles and look at the compass, noting the needed corrections.

I ought to make one for our boat. Maybe the travel lift guy will shift around to 8 points of the compass and hold still, so I can get some accuracy? Probably not.

Good idea.

Maine Sail · #6 (**permalink**) 01-27-2009

I am amazed at the number of folks plying the waters without a properly calibrated compass and a deviation card!!!!

I have mine professionally calibrated every two seasons or any time I make an electronics change near my compass. Read the article in the link below and please find a professional to swing your compass!!!!!!!

I can guarantee that many of your compasses are off... way off!!!!!!!!!! Get them calibrated please!

Charlie is my compass guy and it's some of the best money I spend.

Charlie Cook / Maine Compss Services (LINK)

I guess we've become a point & click sailing forum.. Compass what's that???

tweitz · #7 (**permalink**) 01-27-2009

You sure wouldn't want a compass deviation card made while on a travel lift, unless someone had a plastic or timber travellift.

AdamLein · #8 (**permalink**) 01-28-2009

Maine, I appreciate the need for a proper deviation card in lots of situations, but I also suspect there are many sailors who are almost never in such situations. Day sailors in inland waters who never go out when there's a potential for fog, and carry a GPS... they've (we've) pretty much got it covered.

If I were to plan an extended trip I would certainly calibrate the compass first. I might do it anyway... just for the practice.

erps · #9 (**permalink**) 01-28-2009

Quote:

I am amazed at the number of folks plying the waters without a properly calibrated compass and a deviation card!!!!

I have mine professionally calibrated every two seasons or any time I make an electronics change near my compass

Do you find that the deviation card changes much between your two season checks?

Bene505 · #10 (**permalink**) 01-28-2009

Quote:

Originally Posted by tweitz

You sure wouldn't want a compass deviation card made while on a travel lift, unless someone had a plastic or timber travellift.

Yes, it was a bit tongue in cheek. It would be a funny picture though.