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
Deep Fathom the same time, Jack Kirkland is on an underwater salvage mission in the Pacific, trying to salvage gold bricks from a sunken Japanese ship when an underwater earthquake occurs causing an underwater volcanic eruption and the magma consequently consumes the ship taking all but one brick of the gold with it. Kirkland returns to his ship, a salvage boat - Deep Fathom, with the brick and shares the disappointment with his team when they are radioed by the U.S. Navy to go to a site close to where they are. Though reluctant, the Deep Fathom proceeds towards the co-ordinates given.