1 knot: how many nautical miles per hour and kilometres per hour?

As we know, necessity is the mother of invention, so they came up with a device, which gave rise to a unit later known as ‘the knot’.

The said invention was a chip log a.k.a. Dutchman’s log. It was a floating wooden panel with a long line spooled around it. The line had knots tied on it 14.4018 metres apart from each other. A chip log was cast over the stern of a ship and a sailor let the unrolling line slide through his fingers, and measured the time which passed from touching one knot to another with a 30-second sand-glass.

That was the origin of a unit called ‘knot’, also known as the nautical mile per hour (nautical mile = 1852 m), whose modern value is only 0.02% different from the original measure. It has been agreed in the 20th century that the knot is equal to:

At present, the knot is used in maritime as well as air navigation.

Did you know?

A nautical mile is different from the land mile. The land mile originated from the measure of 1,000 paces of the Roman soldiers. In 1593, Queen Elisabeth I established its length as 5,280 feet.