Conversion from 3 Nautical leagues to Miles

Information about the Nautical league (nlea)

The nautical league is a unit of length equal to three nautical miles, or exactly 5556 metres. It is longer than the land league by about 728 metres, since it is built from the nautical mile of 1852 metres rather than the statute mile.

The unit belonged to an era when it was the practical measure of coastal jurisdiction. The cannon shot rule, articulated in the seventeenth and eighteenth centuries, held that a state's authority extended as far as it could defend from shore, conventionally taken as three nautical miles. That distance became the standard territorial sea limit and was expressed as one marine league. Many older treaties and statutes define maritime boundaries in leagues for this reason.

The three-mile limit held for centuries before eroding through the twentieth. States progressively claimed wider waters, and the United Nations Convention on the Law of the Sea settled the matter in 1982 by establishing a twelve nautical mile territorial sea and a two hundred mile exclusive economic zone. Both figures are stated in nautical miles rather than leagues, and the older unit fell out of legal use.

Charts and pilot books from the age of sail used the league routinely for describing offshore distances and the visibility of landmarks. Reading those sources accurately requires knowing which league is meant, since the same word could refer to a land league, a marine league or a Spanish or Portuguese variant, and the differences are large enough to matter when reconstructing a historical position.

Today the unit has no navigational role. Charts are marked in nautical miles, and distances at sea are quoted the same way. The nautical league appears only in historical and legal texts.

The unit also underlies a familiar figure in visibility calculations. From a height of about three metres above sea level, the horizon lies roughly one nautical league away, which is why the three-mile limit corresponded loosely to what a lookout could see as well as to what a gun could reach.

One nautical league equals 3 nautical miles, 5556 metres, 5.556 kilometres, or about 3.452 statute miles.

Information about the Mile (mi)

The mile is a unit of length equal to 5280 feet, 1760 yards, or exactly 1609.344 metres. The symbol is mi. It is the principal unit of road distance in the United States and the United Kingdom.

Its name comes from the Roman mille passus, a thousand paces, where a pace counted two steps. That unit measured about 1479 metres, appreciably shorter than the modern mile. The English mile grew to its present length because it was reconciled with the furlong, an older agricultural measure. Making the mile eight furlongs required 5280 feet, and Parliament fixed that figure by statute in 1593, which is why the unit is sometimes called the statute mile to distinguish it from other historical miles.

Those alternatives were numerous. The Scots mile, the Irish mile and various German and Scandinavian miles all differed, some substantially. The Swedish mil, still used colloquially, is ten kilometres.

Road signs, speed limits and vehicle odometers use the mile in the United States, the United Kingdom, Liberia and Myanmar, and speeds are given in miles per hour. The United Kingdom's position is inconsistent by design: distances and speeds are imperial while most other official measurement is metric, an arrangement that has survived repeated proposals for change.

Athletics keeps the mile as the one non-metric distance with continuing international standing. World records are ratified over the mile alongside metric distances, largely because of the historical weight of the four-minute barrier broken by Roger Bannister in 1954. The current record stands under 3 minutes 44 seconds.

Fuel economy in the United States is expressed as miles per gallon, and aviation and shipping use the separate nautical mile, which is longer at 1852 metres and unrelated in derivation.

The map of the United States is drawn on it. The Public Land Survey, begun in 1785, divided the western territories into townships six miles square, each containing thirty-six sections of one square mile, and each section of 640 acres subdividing neatly into quarters and quarter-quarters. Roads followed the section lines, which is why so much of the American Midwest is a grid of straight routes one mile apart, and why farms there are described in quarter sections rather than in acres. Anyone flying over Iowa or Kansas is looking at the mile drawn across an entire landscape, two centuries after the surveyors laid it out.

One mile equals 1760 yards, 5280 feet, 8 furlongs, or 1609.344 metres. A five-kilometre race is about 3.107 miles.