Terry Simpson wrote:
>
> I get the impression that a lot of US sailors use Defense Mapping Agency
> (DMA) charts and that they show depth in metres. While searching on this
> topic, I found the following quote:
>
> http://www.ussmaverick.net/reports/31-Jan-2002-18-30.html
That was a light-hearted bit of flotsam from two wave bums out having a
good time. It contains more humor than hard fact, though. First of all,
the Maverick is not a commissioned ship of the line in the United States
Navy. Therefore she does not rate the USS designation.
Secondly, they are apparently unaware of the Metric Act of 1866, the
Mendenhall Order of 1893, and the Metric Conversion Act of 1975.
And, quite obviously, they are unaware that the first coastal survey of
the United States was based on "the committee meter", an iron standard
of the meter brought to the US by Hassler shortly after 1805.
Yes, US sailors are trained to use charts with soundings in meters,
fathoms, and feet. More importantly they are taught to always check a
chart's description block to determine the units used for charted
soundings. I can attest that it has been this way since at least 1970
and that I still teach it in my Celestial Navigation class.
In the mid-70s DMA (now part of NIMA) was producing charts with metric
soundings jointly with the British Hydrographic Office. To the best of
my knowledge, all NIMA paper charts today are cut to lengths and widths
in whole numbers of centimeters. I can't afford the software for Digital
Navigation Charts (DNCs) so I cannot tell what they look like. I'll
guess that the data is metric and that the software allows automatic
unit conversion.
Jim
--
Metric Methods(SM) "Don't be late to metricate!"
James R. Frysinger, LCAMS http://www.metricmethods.com/
10 Captiva Row e-mail: [EMAIL PROTECTED]
Charleston, SC 29407 phone: 843.225.6789
