Once known as Hartley18
Join Date: Aug 2007
Location: Melbourne, Australia
Thanked 85 Times in 85 Posts
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Re: Great Lakes Boaters, Polyconic charts, mph
It is the latitude scale, used to measure distance on a Mercator projection.
So, as a Yachtmaster Instructor, you're telling me that the bit I circled doesn't represent a distance of ten nautical miles??
From wonderful wikipedia: "The nautical mile (symbol M, NM or nmi) is a unit of length that is about one minute of arc of latitude measured along any meridian... By international agreement it is 1,852 metres (approximately 6,076 feet)."
Perhaps it's a good thing I'll never have to sail in that part of the world.
A bad day on a boat beats a good day in the office
Last edited by Classic30; 10-04-2012 at 02:02 AM.
Reason: read the scale wrong