Fathom was upset and rose to the surface. A "shot", one of the forged lengths of chain joined by shackles to form an anchor cable, was usually 15 fathoms long (). A "shackle", a length of cable or chain equal to 12.5 fathoms or 75 feet. In 1949, the British navy redefined the shackle to be 15 fathoms. In Finland, fathom ("syli") is sometimes, albeit seldom, used as a maritime unit, of a nautical mile and of cable length. It is customary, when burying the dead, to bury the coffin at least to a depth of a fathom, or "six feet
Fathom estimated by the user. Water near the coast and not too deep to be fathomed by a hand sounding line was referred to as "in soundings" or "on soundings". The area offshore beyond the 100 fathom line, too deep to be fathomed by a hand sounding line, was referred to as "out of soundings" or "off soundings". A "deep-sea lead", the heaviest of sounding leads, was used in water exceeding 100 fathoms in depth. This technique has been superseded by sonic depth finders for measuring mechanically the depth of water beneath a ship, one version of which is the Fathometer