Cross curves of stability is a set of curves from which the KN values for a set of constant heel-angle values at any particular displacement may be read. Thus, we have a curve for heel angle of 10°, next for 20° and so on. To find KN values for a given displacement volume it is necessary to draw a vertical line and read the values where this line crosses the curves. Nowadays KN values in tabulated forms are used instead of curves.