Nautical Units Converter
The international nautical mile is made up of 10 cables (with 1 cable equaling 185.2 meters).
Presented below is the unit of measurement for sea or nautical miles, along with details regarding fathoms, cable length, and knots.
A fathom measures 6 feet, which is the distance a person can stretch their arms from side to side. This rope was utilized to gauge the depth of the sea.
A cable length refers to the length of a ship's cable, approximately 600 feet.
A nautical mile consists of 10 cable lengths, equating to 6,076 feet.
1 nautical mile = 1.1508 miles
A knot serves as a unit of speed on water, where one knot equals 1 nautical mile per hour.
Nautical units of distance
A fathom is a unit of measurement used in nautical contexts, equivalent to 6 feet (1.8288 m), and has historically been employed to gauge the depth of water. The term originates from the Middle English word fathme, which in turn comes from the Old English word fæðm, and is related to the Danish word favn, signifying a ‘pair of outstretched arms’. For a burial at sea, a minimum depth of six fathoms is officially required, likely giving rise to the expression ‘to deep six’, which means to discard or dispose of something. This phrase is also reflected in Shakespeare’s The Tempest, where Ariel informs Ferdinand, ‘Full fathom five thy father lies’, indicating that his body is lost deep beneath the sea.
A nautical mile is precisely defined as 1,852 metres, or 6,076 feet, which corresponds to 1.151 standard miles. The speed measurement unit for ships, known as the knot, is based on this measurement unit – with 1 knot representing one nautical mile per hour. In historical context, a nautical mile was defined as the length of the meridian arc that corresponds to one minute (1/60 of a degree) of latitude at the equator. The term 'mile' originates from the Latin expression for a thousand paces: mille passus.
A cable's length is a nautical measurement unit equivalent to one-tenth of a nautical mile or roughly 100 fathoms. Due to anachronisms and differing measurement techniques, the length of a cable can range from 169 to 220 meters (185 to 241 yards), depending on the standard applied – 720 feet (219 meters) in the U.S. Navy and 608 feet (185 meters) in the British Navy, with the latter adopting this value. A cable's length, also referred to as cable length or simply cable, represents the standard length for which cables were manufactured. According to the Royal Navy, the length of a ship's hemp anchor cable was historically 101 fathoms.
A unit employed for measuring the lengths of cables and chains, equivalent to 12.5 fathoms (75 feet; 22.9 meters). In 1949, the British Navy revised the definition of the shackle to be 15 fathoms (90 feet/27 meters).