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post #7 of Old 10-04-2012
Classic30
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Re: Great Lakes Boaters, Polyconic charts, mph

Quote:
Originally Posted by jackdale View Post
The OP is correct; on a polyconic or conic chart distances are measured with a distance scale, not the latitude scale. The distance scale on both charts is statute and some of the cautionary notes notes indicate m.p.h., not knots.
Righto.. What's this then?? Looks like nautical miles (and tenths) to me:

Untitled.jpg

I understand that the Polyconic nature of the chart means that lines of lattitude and longtitude aren't necessarily straight up that part of the world, so don't get me wrong, I'm happy to learn something new.

Over here anyways, it's only a "chart" if it's in NM - otherwise it's a "map".

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"Honestly, I don't know why seamen persist in getting wrecked in some of the outlandish places they do, when they can do it in a nice place like Fiji." -- John Caldwell, "Desperate Voyage"

Last edited by Classic30; 10-04-2012 at 12:44 AM.
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