A fathom is a unit of length in the imperial and the U.S. customary systems equal to 6 feet (1.8288 m), used especially for measuring the depth of water. The fathom is neither an international standard (SI) unit, nor an internationally accepted non-SI unit. Historically it was the maritime measure of depth in the English-speaking world but, apart from within the US, charts now use metres.
Standard units in Regensburg: the metal rods are (from left to right) a fathom (klafter), foot (schuch, Modern German Schuh "shoe") and ell (öln, Modern German Elle).
Image: Macclesfield Bank 1920 nautical chart
Image: Macclesfield Bank 1920 nautical chart
The imperial system of units, imperial system or imperial units is the system of units first defined in the British Weights and Measures Act 1824 and continued to be developed through a series of Weights and Measures Acts and amendments.
The former Weights and Measures office in Seven Sisters, London (590 Seven Sisters Road)
Imperial standards of length 1876 in Trafalgar Square, London
A baby bottle that measures in three measurement systems—metric, imperial (UK), and US customary
A one US gallon gas can purchased near the US-Canada border showing equivalences in imperial gallons and litres
