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 more variable: from feet on merchant vessels to either on fishing vessels (from ). At one time, a quarter meant one-fourth of a fathom. A cable length, based on the length of a ship's cable, has been variously reckoned as equal to 100 or 120 fathoms. Most modern nautical charts indicate depth in metres. However, the U.S. Hydrographic Office uses feet and fathoms. A nautical chart will always explicitly indicate the units of depth used. To measure the depth of shallow waters, boatmen used a sounding line containing fathom points, some marked and others in between, called "deeps", unmarked but