The fathom equals exactly 6 feet or 1.8288 meters. It is the traditional marine unit for water depth, used on older nautical charts and in recreational sailing. Modern charts mark depths in metres, but fathoms still appear in maritime literature and older US charts.
Real-world: A "mark twain" reading — made famous by the Mississippi riverboats — meant 2 fathoms (3.66 m) of water, the minimum safe depth.
Read full fathom reference →The statute mile equals 1609.344 meters exactly since the 1959 international definition. It is the official road unit in the United States, United Kingdom and Myanmar. The name comes from the Latin "mille passuum" — one thousand Roman paces. The nautical mile (1852 m) is different and used only in marine and air navigation.
Real-world: London to Edinburgh is about 400 miles by road. A marathon is 26.22 miles. US highways typically post 65–75 mph speed limits.
Read full mile reference →