What is an international nautical mile?
An international nautical mile is exactly 1,852 meters, which is about 1.15078 statute miles. The word 'nautical' distinguishes it from the statute mile used on land.
Because the nautical mile began as one minute of latitude, the Earth's circumference works out at roughly 21,600 nautical miles (360 degrees of 60 minutes each). Navigators measure distance directly off the latitude scale on a chart.
A tenth of a nautical mile is a cable, which is 185.2 meters and is still used for short distances at sea. Minutes and seconds belong to the angles of latitude and longitude, not to the unit itself.
What is a UK league?
A UK league was three miles, or about 4.828 kilometers. The length of a league varied between countries and centuries – three miles is the English figure.
The league has long since dropped out of use in Britain and survives mainly in fiction. Seven-league boots, at three miles a league, would cover 21 miles a step.