Abstract: A groove is formed in a body of ice using a milling cutter to form lines of weakness for breaking up the body of ice. The shaft of the milling cutter is arranged to be supported in an upright orientation such that the shaft extends through a surface of the body of ice into the body of ice. Rotating the shaft as the milling cutter is displaced along the surface forms a groove which can follow a variable path to follow natural obstacles when cutting across a body of ice on a natural body of water for example. The ice milling cutter is compact and therefore safer to use on sheets of ice as compared to heavy equipment conventionally used for breaking up ice.