A huge robotic arm, wielding a waterjet powerful enough to slice through steel, swings into action. It is chopping up the hull of a large ship. The structure, which withstood the power of the sea for decades, yields easily to the cutting jet. Before long, the robot has sliced out a big rectangle of steel. Its task complete, the machine silently moves on to the next section. "You can have robots starting at the bow and the stern, and two points in the middle, and working towards each other," says Bryce Lawrence, operations director at Leviathan. The firm, based in...