Application of variation 4

Your True Course is 020 degrees and the Magnetic Variation for the year of 1993 is 6 degrees and
00 minutes West. The annual rate of change is increasing 7 minutes, your task is to calculate the Magnetic Variation for the current year, and to find your Magnetic Course.
Firstly calculate the correction of the Magnetic Variation for the current year, in your case 2002.
Apply the following formula: Correction for the current Year = (current Year – Variation observed year) x Annual rate .
This means the correction for the current Year = (2002 – 1993) x 7 = 63 minutes or 1 degree and 3 minutes (increasing).
Secondly, calculate the Magnetic Variation for the current year using the following formula: Magnetic Variation for the current year = chart Magnetic Variation +/- correction for the current year.
We use + when the correction for the current year is increasing. We use – (minus) when the correction for the current year is decreasing.
This means the Magnetic Variation for the current year is 6 degrees 00 minutes + 1 degree and 3 minutes, which = 7 degrees and 3 minutes west.
Thirdly, convert the True Course to a Magnetic course, using the formula:True to Magnetic: add Westerly Variation and subtract Easterly Variation.
This means the Magnetic course is 020 degrees + 7 degrees and 3 minutes, which = 27 degrees and 3 minutes.