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Old 30-11-2011, 09:25   #76
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Re: Reading a Chart in Metres

Actually,I was thinking "length as spectrum" -not as a unit of an arbitrarily- chosen wavelength which is an angstrom I think.Merely a flight of fancy..doing mathematics with spectrum interference.
PS: Waves are more than length.Waveforms.
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Old 30-11-2011, 09:34   #77
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Re: Reading a Chart in Metres

For the OP,a very simple slide rule would be the easiest way of fast conversion.or just a slider on a ruler having both scales.
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Old 30-11-2011, 09:53   #78
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Re: Reading a Chart in Metres

medicine in usa uses metric now--isn to difficult to convert...
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Old 30-11-2011, 10:42   #79
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Re: Reading a Chart in Metres

How do you tell someone that their system doesn't work, when they has used it successfully for 100 yrs.
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Old 30-11-2011, 11:00   #80
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Re: Reading a Chart in Metres

Quote:
Originally Posted by HappySeagull View Post
For the OP,a very simple slide rule would be the easiest way of fast conversion.or just a slider on a ruler having both scales.
This what I've been using for the past 30 years. As long as they don't change the standards, it's as EZ as the push of a button.


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Old 30-11-2011, 11:17   #81
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Re: Reading a Chart in Metres

metric is actually much easier than our usa system.... makes more sense.
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Old 30-11-2011, 11:27   #82
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Re: Reading a Chart in Metres

In Canada our charts are mostly metric except for a few that still use fathoms and feet. Our official tide tables use both feet and metres, but corrections are done in feet only.

There was huge uproar a few years when there was an announcement that the corrections would be done metres. We are still making the corrections in feet.

That uproar will be miniscule compared to the day when we all agree that chart datum will lowest astronomical tide.
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Old 30-11-2011, 12:24   #83
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Re: Reading a Chart in Metres

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metric is actually much easier than our usa system.... makes more sense.
OK, then you are ready for the next step, total metric navigation

I haven't heard much about this subject for, say 20 years, but at that time, it was said to be scheduled for about 2015. I wonder if there is an obscure international committee plotting this change, behind closed doors?

One possible scenario could run like this.
Replace 360 degrees with 400 "gons". The latitude of the poles would then be 100 gon ( N or S). A "centigon", 1/100 th of a gon, also equal to 1/10.000 of the arc from the equator to the poles. And.... as the original definition of a meter was supposed to be 1/10.000.000 of the distance from the equator to the pole....a "centigon" would also equal 1 km (kilometer) similar to todays minute of arc being equal to a mile (M) or 1852 m, and with similar accuracy. With this "minor" change all speeds would naturally be measured in km/h, boat speed and wind speed alike.
Thinking about it, this must be an easy feature to implement in OpenCPN, just a few magic numbers here and there in the code.
Any early adopters for an alpha test??



Thomas
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Old 30-11-2011, 13:04   #84
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Re: Reading a Chart in Metres

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wind speed

Winds are measured by meteorologists in m/s (metres per second) and then converted.
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Old 04-12-2011, 17:54   #85
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Re: Reading a Chart in Metres

Just a note on drying heights.

If the large number is underlined it means that the area will be above the waterline at LAT.

Trap for young players that think they have more room below than they actually have
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Old 04-12-2011, 20:11   #86
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Re: Reading a Chart in Metres

Dog Gone it How am I going to re-work my Lead Line ??? I find it still tells me depth in fathoms no matter what the chart says ?? I guess Im gonna have to learn Metric after all LOL and at 73 this will be hard !! Bob and Connie and PS got our new boat ! be aboard by new years we hope.
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Old 04-12-2011, 21:59   #87
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Re: Reading a Chart in Metres

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Dog Gone it How am I going to re-work my Lead Line ??? I find it still tells me depth in fathoms no matter what the chart says ?? I guess Im gonna have to learn Metric after all LOL and at 73 this will be hard !! Bob and Connie and PS got our new boat ! be aboard by new years we hope.
Keep your lead line in fathoms. If you are worried about a meter being 3" longer that a yard (.5 fathoms) in your going places you ought not to go.
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Old 04-12-2011, 22:47   #88
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Re: Reading a Chart in Metres

Jackdale, it was a Humerous statement, Ive been at this for over 50yrs and have never not gotten home yet ! LOL, bob nad connie
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Old 05-12-2011, 00:35   #89
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Re: Reading a Chart in Metres

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Eh? ...

As someone else mentioned, the main issue is when you are converting between units. Having used both systems for many years, I can now say that I prefer metric for virtually everything.
x2 on that. The Imperial system was the worst invention of mankind. Until the USA trumped Imperial stupidity by inventing a smaller gallon ...

Gallons, cables, chains, furlongs, fathoms, feet, pints, gills, pounds, ounces, shillings ... OMG!
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Old 05-12-2011, 02:56   #90
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Re: Reading a Chart in Metres

OK, it will be hard to drift this thread further but I will give it a go.

Which is heavier, a pound of gold or a pound of feathers?
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