I prefer not to use it and teach our students the same. It aids in adjusting declination, which we will cover later. Index Line: This immovable line lies directly beneath the compass dial.

In the U.S., the angle of declination varies from about 20 degrees west in Maine to about 21 degrees east in Washington. (See Figure 6.7). The magnetic field lines of the earth are constantly changing ...

Once you have your declination, adjust your compass with ... Turn the housing so north lines up with the direction of the travel arrow. Turn your body (not just the compass) so the magnetic ...