Jozef wrote:
....

Major disturbances of the magnetic field would affect both compasses I
suppose.
The readings of the RECTA are close enough to rule these out.

These measurements are done over and over and by different persons with
almost the same results (within 0.5°).



It seems as though you have a good grasp of the concepts here, and it
appears that the Steiner has come up lacking. There are still a few
possibilities. I was going to mention temporary magnetic fields from
motors and speakers, but this is unlikely in a field, unless you were
using your iPod or cell phone during the Steiner test. I had a learning
experience years ago where a small portable radio sitting next to the
compass shifted our course 15 degrees.

Another possibility is that the compass is built for the southern
hemisphere, where the "dip" is different. I'm not sure if this problem
would manifest itself in this way, but its worth considering. I assume
the serial or model number can be used to track down the latitude the
compass is set for.
http://www.steiner-binoculars.com/do...mpassZones.pdf

And of course, its possible that this is a manufacturing or design flaw.
Steiner (like most companies) doesn't publish any specs for compasses,
but 7 degrees seems like a lot, especially since the field of view is
only 7 degrees.

Please let us know how this turns out. Nowadays, most sailors simply
use a GPS, but not too long ago hand bearing compasses were a primary
navigation tool, and I remember debates as to whether a dedicated
compass was better than one built into the binoculars (I favored the
former).