 The innovation was a 'sense' aerial which when switched in, suppressed the ellipse in the 'wrong' direction leaving only the correct bearing.With this there was hardly any need to triangulate—the escort could just run down the precise bearing provided, estimating range from the signal strength, and use either efficient look-outs or radar for final positioning.Many U-boat attacks were suppressed and submarines sunk in this way—a good example of the great difference apparently minor aspects of technology could make to the battle.