NorthStar 961 Reference Manual page 292

Chapter 13 - Customizing Setup Functions
Magnetic
variation
Page 13-22
3. When done, press the ACCEPT key (or CANCEL to leave
the option unchanged).
4. Press RETURN to go back to the SETUP MENU screen.
Magnetic compasses naturally point to the magnetic north
pole, which is several hundred miles from the Earth's
geographic north pole. The difference between the angles to
the two poles is called magnetic variation. To coincide with a
magnetic compass, the AUTO setting is the default for
magnetic variation. Under most conditions, you'll want to
automatically calculate the variation for your position.
However, you can also select manual magnetic variation or
true north.
True north setting
If you select true north, no corrections will be applied to your
course and bearings. True north usually is required if you're
using a gyrocompass.
Automatic setting
If you select automatic variation, magnetic variation is
calculated automatically, according to your position, to
coincide with a magnetic compass.
Manual setting
If you select the manual setting, you can enter from 0 to
180 , East or West, in the MAG VARIATION field. The manual
setting is available for those times when the CHART screen
must match an older or less accurate chart, or in remote areas
as when you're above 70 north latitude, where, locally, the
variation calculations can be off by a significant amount.
To change the magnetic variation setting:
1. At the NAVIGATION SETUP screen, press the CURSOR
PAD to highlight the MAG VARIATION option, then press
the EDIT key.
961/962 Operations and Reference Manual, Rev. A