Nautical mile what is

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Definition of nautical mile. Examples of nautical mile in a Sentence Recent Examples on the Web The turbines will be one nautical mile apart, too close together for some boats to navigate safely. Eskridge, 54, worries that the turbines could hurt his catch. First Known Use of nautical mile , in the meaning defined above. Learn More About nautical mile.

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At sea, in navigational calculations, the statute mile is considered an arbitrary length of no particular significance. And, in particular, the replacement of the ordinary measurement with nautical miles and knots at sea helps the Mariners to quickly read charts that use latitude and longitude.

Currently, the nautical mile is used as the unit of measurement by all countries for air and sea navigation. A nautical mile, a unit of measurement defined as 1, meters or 1. If one is to pick a part of the earth after cutting the planet in half at the equator and consider the equator as a circle, it can be divided into degrees.

Then, one degree can be split into 60 minutes, of which one minute of arc on the planet Earth is 1 nautical mile. According to the English measurement system, a nautical mile is equal to 1. Then comes the knot. Of course, here we are not talking about sailing knots, such as Figure-8 Knot. Similar to the speed and distance measurement on land, the nautical mile and knot explain the movement of a vessel at sea.

For instance, a boat or ship travelling at 15 knots could go 15 nautical miles per hour. Since the beginning of ocean navigation, a number of methods have been brought in for making the voyage through long and vast seas easier. Several traditional practices, using geometry, astronomy and even special instruments, helped sailors to navigate to their destinations for a quite long period.

Sometimes, in addition to their know-how tools, it was just luck that protected them when they ventured out into the uncharted, dangerous waters. In the later periods, the mariners succeeded in developing charts depicting distant shorelines and common features of the sea during voyages.

According to historical records, such charts developed in the earlier period were marked with simple outlines of coastlines made to support written or oral directions. In addition to these, compasses, astrolabes, and callipers were the tools that were in use by ocean navigators in earlier times. Primarily, this compass was used to determine the direction of the wind when the sun was not visible. Similarly, the cross-staff, astrolabe, and quadrant were in use to help sailors determine latitude in several stages of maritime navigation.

As km is still quite a large distance to relate to, we can break it down further. To realise the full potential of equating the nautical mile with a minute on the equator, you have to look at the shape of the Earth.

The Earth is actually an oblate spheroid, but we can approximate it as a sphere. We need to use spherical trigonometry to successfully navigate on the surface of a sphere. Spherical trigonometry effectively gives you courses and distances in degrees and minutes.

Linking the nautical mile to degrees and minutes means it is simple to turn it back into a distance we can understand. There is nothing stopping you from using the statute mile in your calculations. You would just be adding an extra layer of complexity and introducing a potential source of error.

Of course, if you start transposing your calculations to be in statute miles, you also need to transpose all your equipment to give statute miles as well. Historically we have always used the nautical mile, so that is how everything is set up.