Cable Length

One tenth of a nautical mile, and originally the working length of a ship’s anchor cable.

The cable began as a practical object rather than an abstraction: it was simply how much anchor cable a vessel carried, and it settled at around a hundred fathoms because that was the depth in which anchoring was realistic. The Royal Navy fixed it at 608 feet, exactly a tenth of the Admiralty nautical mile of 6,080, and the modern international figure of 185.2 metres keeps the same relationship to the international nautical mile. Short distances at sea are still reckoned in cables rather than in fractions of a mile, since a warship manoeuvring in company thinks in hundreds of yards rather than in decimals.