How many feet are in a fathom?
Answer: 6 [six]
Typically a measurement for nautical depth, a fathom measures 6 feet, or roughly the length of the average sailor’s arm span fingertip to fingertip. In fact, that’s where the name “fathom” comes from. It’s derived from the Old English words for outstretched arms, faedm or faethm. The Mariana Trench, the lowest point in any of Earth’s oceans, is more than 6,000 fathoms deep, several thousand feet deeper than Mount Everest is tall. Source: Encyclopaedia Britannica, MarianaTrench.com
A fathom is a unit of length in the imperial and the U.S. customary systems equal to 6 feet (1.8288 metres), used especially for measuring the depth of water.
There are two yards (6 feet) in an imperial fathom. Originally based on the distance between a man’s outstretched arms, the size of a fathom has varied slightly depending on whether it was defined as a thousandth of an (Admiralty) nautical mile or as a multiple of the imperial yard. Formerly, the term was used for any of several units of length varying around 5–5 1⁄2 feet (1.5–1.7 m).