Convert Nautical League (UK) (nl (UK)) to Fathom (fath) instantly.
About these units
Nautical League (UK) (nl (UK))
This older British unit corresponds to 3 UK nautical miles, or 18,240 feet (about 5,563.6 meters), slightly longer than the international version. Before international standardization, distances in British naval operations were often recorded using UK nautical leagues, especially in long-range maritime planning. Like other historical British units, the UK nautical league reflects the era when each naval power maintained its own measurement standards. While no longer used for navigation, it appears in historic ship logs, naval battles, and exploration records—especially for events predating the 20th century. For historians, the distinction between the UK league and the international one is critical to accurate interpretation of maritime distances.
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.