Sunday, February 2, 2014

One Mile Per Minute





One Mile Per Minute

The length of any meridian of Longitude is measured as 180 degrees from North Pole to South Pole.  Each degree is a degree of Latitude.  The Equator is zero degrees Latitude.  Spokane is at 47.62 degrees North Latitude - - or ~ 47 degrees, 37 minutes North Latitude.

Each degree of Latitude is divided into 60 minutes.  And each minute is 1,852 meters long; or 6,076 feet (equaling a nautical mile).  So, when you look at a NOAA nautical chart, the Latitude scale along the left and right margins shows nautical miles alternating in black and white colors vertically.  Often each nautical mile is shown divided by lines representing one tenth of a nautical mile.  If you are using part of the chart where the distance scale at the bottom or the top of the chart is not visible, you can always use the Latitude scale along the left or right edge to get an accurate distance measurement.

How far is it across Drayton Harbor from the Red light at the marina entrance to the tank on Tongue Point???  Looks pretty close to 600 yards (1,800 feet or about a tenth of a nautical mile)… 


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