What is a good steering compass?

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Originally Posted by Dave22q

increments smaller than 5 degrees are difficult to read unless the compass is extremely large. A good steering compass depends on the size of your boat and how you use her. I never worry about course deviations of a degree or two as wave and wind action makes holding course an averaging process. About the only time I want precision is in navigation when sighting a mark but that is using a different instrument entirely (hand held sighting compass).

That is very helpful I was thinking deviation would only be a degree or two and i could ignore it for the most part, in practice, and I could just fix my positon more often and get back on track. I have an iris 50 hand bearing compass, which seems superb, a real good bit of kit.

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Originally Posted by alansmith

Yes, the military has the ability to "dither" the GPS system in times of threat. I think if an ICBM with dozens of hydrogen bombs lit up san Francisco it would not matter if they had dithered the GPS or not.

There are many reasons to be good at compass work. Remember the line from the movie "White Squall" with Jeff Bridges...when the Cuban military boat commander smashes the ship compass...and Jeff B. tells the commander that a real sailor just has to look at the stars to know where he is...or something like that. There is a pride gained in skills learned is what I would say.

You will learn why you were a couple of miles off of your dead reckoning when your compass course was correct, wind steady, boat speed pretty well known...maybe you were traveling due north but a current was flowing across your course at some degree tangential to your course. Then when you travel that way again you will remember how much to offset that course heading to allow for the current.

Learning new skills is good for the brains development and I would say healthy for it to solve problems and make connections between hundreds of different little things. You will learn how to use map and compass, prevailing winds, currents, and obstacles to get where you want to go. How cool is that? Become your own master and depend on your own brain to solve issues involved with navigation. It is its own sweet reward. Any skipper here will tell you that there is deep satisfaction in knowing how to use map and compass without electronics. Sailors have been doing it for thousands of years. The south pacific sailors did it with stars and had no magnetic compasses. Only in the last several decades have sailors had the luxury of knowing where they are to a foot or less. Electronics are wonderful...but you better be good with map and compass if you are really planning serious blue water passages, caught in a fog bank, and you are trying to count the seconds between the blasts to know which buoy that represents on the charts...Map and compass work is just so much fun and deeply rewarding...

Yes, I am aiming to be able to do it all without the need for electronics, just for the satisfaction. There is a historical aspect to it all for me. To be off the north east coast of England, and visualizing 500 viking longships coming in from over the North Sea to enter the Humber Estuary with its shallow and moving sands, and strong eddying currents and great tidal range, and then 'going in with them'. So navigating manually makes such a daydream more vivid. I'm a history fan.

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Originally Posted by MBWhite

For a 22ft cabin cruiser I would suggest purchasing an electronic compass, for a lot of reasons. To begin with, it will be more accurate as it is easier to calibrate than even the most expensive magnetic compass. It will be easier to read in rough conditions too when a traditional compass is bouncing all around.

On ebay and elsewhere, you can buy them for under 10 pounds if you are under a budget (and everyone is, just the number changes and not that I recommend purchasing the absolute cheapest thing possible). Anyway, I would get something there, and after calibrating it to your boat use it to calibrate your magnetic compass. You don't even need to fiddle with the magnetic compass, just make up a card:


Do this with your compass in its mount and the engine running. Just steer the magnetic course on the electronic compass and write in the box what the magnetic compass reads. You can also make up a second card taking the magnetic variation into account, so the card can tell you what compass course to take for a true heading. (there are other ways of doing it but since you are asking here you don't know them yet. When you do know them you won't necessarily need a second card but it can help for now and you will know when you do not need it any more).

Anyway, that is how I would approach your problem. To purchase a quality magnetic compass and have it professionally swung would cost more than purchasing a cheap electronic one AND paying to take a navigation class which actually might just cost less than the compass which is what I would recommend.

Cheers for this. I will try one of those electronic compasses just so that I know about them. They seem interesting. And I willhave a go at making a deviation card. I will try it as you suggest. Should be interesting to see how it works.

I think all this stuff is worth learning about. I just bought a cabin barometer, brass, by plastimo, a 3 inch dial. It works fantastic. It really predicts the weather in terms of going to get worse or going to get better, and this is how they used to do it with things like that. I could easily have skipped getting one, am really glad i tried one. So I will order one of those electronic compasses just to see what they can do. Another thing is a little hand-held anenometer I have. Know it is going to be very useful. I'm going to have to be careful, I'm getting slowly sucked into this mariner thing,and I have been resistantly dipping my toe in it all. Thanks for the reply. Cheers.