Compas ajusting

[copaco]

On Compas ajusters.com au Australia there is a DIY counter- clockwise Compas rose. I gather that you must be situated on an eastern longitude for this method be valid? Be it the bearing method or sun shadow method?

[Pete7]

Not quite sure I follow this, do you have a picture?

Some diving compasses have a reverse compass rose which I always found confusing, so took my orienteering compass with me underwater.

[requiem]

Longitude wouldn't matter; the earth doesn't care where we put the prime meridian.

The difference between using a regular and reversed dial has to do with how you are reading the compass. If your dial doesn't rotate and you are instead reading the number at which the needle is pointing, a reversed rose will give you the correct direction.

If the dial itself rotates (or can be rotated) to align north on the dial with north, the non-reversed dial is used. In these cases you read off the direction using the lubber line or other external reference, as the needle (if there is one) should always be aligned with north on the dial.

Example: You hold a reversed compass facing north; the needle points to "N" on the dial. You turn left to face left; "N" on the dial is now aligned with west, so you instead read from the needle. The needle is still pointing north, which is to your right. On a traditional rose it would be pointing to an "E" on the dial, but you aren't facing east in this example, thus the reason for reversing the rose.

[copaco]

Excellent!

[tkeithlu]

I'm going to borrow your explanation, Requiem. That's very clearly stated. Try the best little hand bearing compass (degrees on card) made, the Sunnto KB-20.

[copaco]

I also have the new Suunto with magnefier on top.

[StuM]

Originally Posted by tkeithlu

I'm going to borrow your explanation, Requiem. That's very clearly stated. Try the best little hand bearing compass (degrees on card) made, the Sunnto KB-20.

Personally, I like my Plastimo Iris 50

[requiem]

Originally Posted by StuM

Personally, I like my Plastimo Iris 50

I like it too, but I wish the needle settled anywhere near as fast as my Suunto MC-2. Which reminds me, I need to add a front sight to my Plastimo...