<story><title>The eye of hurricane Matthew passes directly over a weather buoy</title><url>http://www.ndbc.noaa.gov/show_plot.php?station=42058&amp;meas=wdpr&amp;uom=E&amp;time_diff=-5&amp;time_label=EST</url></story><parent_chain><item><author>Justin_K</author><text>FYI a Knot is standard for navigation world wide because the unit is standardized on earth&amp;#x27;s size.  1kt = 1 nautical mile per hour.  1 nautical mile = one minute of Earth&amp;#x27;s longitude.  Learned this in sailing class :)&lt;p&gt;Wikipedia: &amp;quot;Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels approximately one minute of geographic latitude in one hour.&amp;quot;</text></item><item><author>gilgoomesh</author><text>That&amp;#x27;s a beautiful graph but NOAA&amp;#x27;s insistence on non-metric units frustrates me endlessly. Knots for speed are bad enough but &amp;quot;inches&amp;quot; for pressure is multiple levels of wrong.</text></item></parent_chain><comment><author>gilgoomesh</author><text>Using &amp;quot;Knot&amp;quot; because it&amp;#x27;s tied to longitude and latitude is the exact point the metric system is designed to avoid: needless and &lt;i&gt;inaccurate&lt;/i&gt; attachments between system of units and specific phenomena that actually complicate rather than simplify and hinder interoperation with every other system.&lt;p&gt;As you state:&lt;p&gt;1. a knot is only &lt;i&gt;approximately&lt;/i&gt;  equal to 1 min of latitude per hour (there are numerous cases where it&amp;#x27;s unusably wrong)&lt;p&gt;2. doesn&amp;#x27;t really help for longitudinal travel&lt;p&gt;3. maps are continuously projected to favor this mediocre form of navigation instead of something more accurate (see Mercator projection)&lt;p&gt;4. you could easily put kilometre lines on your charts instead of minutes of latitude and fix all the previous problems</text></comment>
<story><title>The eye of hurricane Matthew passes directly over a weather buoy</title><url>http://www.ndbc.noaa.gov/show_plot.php?station=42058&amp;meas=wdpr&amp;uom=E&amp;time_diff=-5&amp;time_label=EST</url></story><parent_chain><item><author>Justin_K</author><text>FYI a Knot is standard for navigation world wide because the unit is standardized on earth&amp;#x27;s size.  1kt = 1 nautical mile per hour.  1 nautical mile = one minute of Earth&amp;#x27;s longitude.  Learned this in sailing class :)&lt;p&gt;Wikipedia: &amp;quot;Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels approximately one minute of geographic latitude in one hour.&amp;quot;</text></item><item><author>gilgoomesh</author><text>That&amp;#x27;s a beautiful graph but NOAA&amp;#x27;s insistence on non-metric units frustrates me endlessly. Knots for speed are bad enough but &amp;quot;inches&amp;quot; for pressure is multiple levels of wrong.</text></item></parent_chain><comment><author>LeifCarrotson</author><text>Latitude, not longitude - the length of one minute of longitude changes with your distance from the equator.&lt;p&gt;Also, I am not sure how that&amp;#x27;s relevant to NOAA?</text></comment>