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Old 03-05-2014
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Re: GPS Accuracy - how much is actually needed

Maine-
Let's see. With a chart scale of 1:25,000 and a common 0.5mm mechanical pencil, unsharpened, that pencil line would be 25,000 x 0.5mm wide in the real world. 12,500mm at 1000 mm to the meter, 12.5 meters wide.
But if you buy that mechanical pencil at a real supply store it can easily be 0.3mm lead, giving us 25,000 x 0.3mm, which will be 7.5 meters wide in the real world.
I'm not sure if you can sharpen a conventional pencil to a finer point.

Of course if the navigator is using a vintage 5/0 or 6/0 Rapid-O-Graph, they can do twice as well as that.

Personally I prefer the safety zone created by a nice dull Crayola Crayon. (G)

But back to the OP's question: Offhand, anytime you can increase accuracy or precision, that's a good thing. What they are seeing is a signal degradation caused by the hull and deck, and that probably will increase under heavy rain and cloud cover. Ten meters, twenty meters..."Good enough for government work."
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