Map Grid Location
Maps are circumscribed by lines. Those parallel to the equator are called lines of latitude with each minute of latitude is equal to one nautical mile. The lines passing through the poles are known as lines of longitude. The spacing of these lines varies as they traverse from pole to pole and are only equal to one nautical mile apart at the equator.
A particular point might be referenced as 44o 42' 00" N and 79o33'00" W, which would place the point of interest in the Province of Ontario in Canada. Below is a sample of the grid that might be found on a VNC chart where there are major grid lines every 30 minutes of latitude and longitude, as opposed to every degree. The dashed lines in the illustration below show how the grid is used to locate this point.
