Compass Questions

S

sketchrbob

New member
I posted the questions below on the "New Kid on the Block" post but due to the Subject title not many saw them. As I indicated on that post if there is interest we could take up one question a week and give time for everyone to ask their questions about it or discuss it or both. It should probably be in a different Forum than General Discussion. Would anyone like to suggest an appropriate category?

Everyone: From experience I already know what some of your questions are. And if you don't want to know that is OK too. Some of your questions will be:

1. What do I do if I have a bubble in my compass?

2. What is the "best" type of compass for a C-Dory? You may be surprised!

3. How do I go about installing my own compass?

4. How do I adjust my own compass?

5. What is the "best" hand bearing compass?

6. How do I coordinate my compass and my GPS?

7. If I have a good GPS, why do I need a compass?

8. Which is better, a flush mount or a binnacle mount compass?

9. What is the best product for polishing the dome of a compass?

10. What is meant by a sticking pivot? If I have one, what should I do about it?

11. Any other compass question on your mind?


Please note in my E mail address there is only one "e" in sketchrbob. Thanks.

Bob W.
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I can only answer some of the questions. I use Ritchie for my fixed compass, mounted just aft of the center window. I have a hand bearing compass, but I've never had to use it. Coordinating between GPS and magnetic compass is simple; I get on course using my Garmin 2006, then look at my magnetic compass, and whatever it reads, I subsequently use. Saves on compass deviation calculations, and the magnetic compass reacts more quickly than the GPS unit, so it's easier to track if you don't have a landmark to folllow. If the several GPS units go out, I'm glad I have a magnetic compass to fall back on. For the rest of the questions, somebody else with have to chime in.
 
Bob,

I'd be pleased to have you go through your list of questions in approximately the order you provided above. I'm sure I'd learn plenty from a master such as yourself.
 
Welcome aboard, and thoughtful questions. In the interest of prompting your responses I will throw out some answers. Note, I said the questions were thoughtful not my answers.

1. What do I do if I have a bubble in my compass?

Add mineral spirits. Some compasses are better than others at withstanding the temp extremes involved with winter storage and summer cabin temps. Never gets cold in ME tho, eh?

2. What is the "best" type of compass for a C-Dory? You may be surprised!

Bigger is better. Less bouncing around. Best compass is one you will use. I prefer a large flat card compass directly in line with the helm. I like a flat card over direct reading by old habit. Also more intuitive for guests to turn the desired direction if I ask them to turn 5 degrees when trolling, etc.

3. How do I go about installing my own compass?

A string fore and aft helps you center it on the helm and your line of vision. A much debated topic around here but I install the compass first, not the electronics, the rest must fit around it and not cause uncorrectable interference.

4. How do I adjust my own compass?

Swinging ship. I think this is far easier with GPS than formerly with known courses, ranges, etc. Do it on the water not on your metal trailer. A little at a time on all courses and keep a table.

5. What is the "best" hand bearing compass?

One that is readily at hand and usable at night. I don't have experience with binocs with compasses in them. So not sure what you are asking but hoping for a good recommendation.

6. How do I coordinate my compass and my GPS?

Dress them in matching outfits? GPS gives you magnetic or true and will also give you deviation. Local deviation can be significant in the Great Lakes because of iron deposits, etc. Still have variation of course. This seems a sub topic of swinging ship, again curious for your answer.

7. If I have a good GPS, why do I need a compass?

Why boat when you can drive or fly? Sorry, this has been debated often on this forum. Some reasons may be: useful when at rest (don't have to be moving to know your direction), quick reaction to small changes in course, not reliant on electric power, lovely boat jewelry. This topic is similar to why do I need paper charts?

8. Which is better, a flush mount or a binnacle mount compass?

I don't know? In our dories a flush mount or short binnacle mount gives the best view. I suppose binnacle mounts may be more easily adjusted? Again I prefer a flat card but don't have a preference here.

9. What is the best product for polishing the dome of a compass?

Most folks who see my boat know that I am not too familiar with polish. So again look forward to your response.

10. What is meant by a sticking pivot? If I have one, what should I do about it?

Chapman (or someone) points out when you shop for a compass to test it with your pocket knife or whatever. See if the dial moves freely. See if it returns to rest consistenlty at the same spot when the object is pulled away with good damping, etc. I presume a sticky pivot means the card sticks a bit before it starts to move. So short of serviciing it, maybe do a series of 360 degree turns to loosen it up?

11. Any other compass question on your mind?

What is the oldest one you have, and how is it working?

Thanks for listening.

Mark
 
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