Quote:
Originally Posted by geogymn
Wldrns, I am going to start from point "A" and head straight to point "B" exactly 1 mile away. I forget to figure the 13% declination. After walking a mile by how my yards did I miss my target. Is there a simple mathematical equation or do you need a Trig. equation?

Technically it is a trigonometric problem, But for an easy rule of thumb(for relatively small angle errors), you will have approximately a 1 in 60 cross course distance displacement error for each degree of heading error. In other words, consider traveling 1 nautical mile (about 6,000 feet). one part in 60 of 6000 is 100, therefore you will be displaced from your goal by 100x13=1300 feet missing your target. in your case ( in this region of the country) you will be that much too far to the left of target if you have ignored magnetic declination.