It is getting harder to download the Military Field Manual
Here is the essential parts of the ,
Compass, Land Navigation Field Manual
Simplified Files that cover the basics.
Compass_how_to_avoid_getting_lost.pdf
Compass Standard Inst 2006_2.pdf
Land_Nav_from_Marine_Combat_Skills_1B.pdf
Seabee 05 Land Navigation [Compass].pdf
Navigation and Tracking, Jungle.pdf
Manual Itself
Compass ch06 Direction [THEORY].pdf
Compass ch09 Land Navigation [COMPASS].pdf