Reliable Compasses for Cruising

[KP44]

Originally Posted by Jon Hacking

…. in NE Indonesia .

I presume you ordered southern hemisphere?

[Jim Cate]

"purchased in San Francisco.... and before long (somewhere around 30 deg S IIRC) it hung up and stopped working.
And that's actually sort of normal. Conventional compass construction is such that you either buy one built for the northern or southern hemisphere, and expect that even if the compass keeps working, it will no longer be accurate in the other hemisphere.

HS, I think you are quoting me in the above (it's nice when you attribute quoted statements, btw) and the point of my post was to show that while our Danforth compass did fail to operate in the deeper south, our friends Ritchie worked all the way down to NZ and later to the south of Tasmania without re balancing. There is a difference in design, and IME the Ritchie was better in dealing with this issue. And as long as the card is free to rotate, there should be no significant degradation in accuracy when the dip angle gets steeper.
Perhaps the response time will increase, but the compass should still point to magnetic north. At extreme latitudes, magnetic compasses seem to fail as the dip angle approaches vertical... I have no intentions of checking this out personally!

Jim

[mako]

By the number of responses to your thread it would appear that "opinions are like compasses - everyone has one!"

Anyway, my Ritchie was 40 years old and flawless without service. But I understand that the Plastimos have excellent long term performance and are extremely affordable compared to the big-R.