Convert Fathom (fath) to Foot (US Survey) (ft (US)) instantly.
About these units
Fathom (fath)
A fathom is equal to 6 feet and is historically associated with maritime measurement. Its origins may lie in the approximate span of a fully outstretched human arms, which was convenient for measuring rope lengths by hand aboard ships. Sailors used the fathom to estimate water depth through weighted lines, giving rise to the practice of "sounding" the depths. The fathom became a cornerstone unit in nautical life because it fits the human scale while also being large enough to measure significant underwater distances. Charts, sonar readings, and older depth gauges frequently utilized fathoms, although modern equipment increasingly displays depths in meters. Still, many mariners—particularly in regions using imperial measurements—continue to think instinctively in fathoms when estimating safe anchoring or navigating shallow waters. The unit persists as an important piece of maritime history and remains in active use by traditional sailors, divers, and some fishing industries. Its survival reflects the enduring cultural heritage of nautical practice.
Foot (US Survey) (ft (US))
The US Survey Foot is a standardized version of the foot, defined as exactly 1200/3937 meters (~0.30480061 m). It was adopted to maintain continuity with older surveying records when converting to the metric system. Surveyors, engineers, and geographers in the United States used this unit for mapping, cadastral surveys, and infrastructure projects. Its slight difference from the international foot allows historical survey data to align accurately with modern geodetic coordinates. Although the international foot is now more common, the US survey foot remains relevant for interpreting historical survey data and legal property boundaries.