Convert Fathom (fath) to Mile (US Survey) (mi (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.
Mile (US Survey) (mi (US))
The US Survey Mile equals 5,280 US Survey Feet (~1,609.347 meters). Slightly longer than the international mile due to the use of the US survey foot, it has been essential for mapping, transportation planning, and geodetic calculations in the United States. Surveyors and engineers relied on the US survey mile to ensure precise alignment of property boundaries, railroad tracks, and infrastructure projects. Over long distances, even small differences between the US survey and international mile can accumulate significantly, necessitating care in measurement. Though the international mile is now standard, the US survey mile remains important for interpreting historical maps, legal descriptions, and older engineering plans.