The unit a 'cable length' is named after the length of a ship's anchor cable in the Age of Sail. What is an international cable length?

Explanation

A nautical mile is a unit of measurement defined as 1,852 metres (1.1508 mi). Historically, it was defined as one minute of latitude, which is equivalent to one sixtieth of a degree of latitude. Today it is still used in both air and marine navigation. One tenth of a nautical mile is a cable length. The derived unit of speed is the knot, defined as one nautical mile per hour. The geographical mile is the length of one minute of longitude along the Equator, about 1,855 m.