by Gavin99 » Sun Jan 27, 2013 12:04 pm
Hi Islayhawk , as MacCookie suggests one figure is the angle between magnetic and grid north(magnetic angle ) ,eg Islay Airport , 1deg 2 min west (July 2012)
The other figure is the angle between grid north and true /geographic north (magnetic declination) , at the Airport this is 4deg 25min west .
The magnetic / grid angle is the one to use when taking bearings and map reading