This wave force is called the Froude-Krilov force, which follows from an integration of the pressures on the body in the undisturbed wave.
Actually however, a part of the waves will be di¤racted, requiring a correction of this Froude-Krilov force. Using the relative motion principle described earlier in this chapter, one …nds additional force components: one proportional to the vertical acceleration of the water particles and one proportional to the vertical velocity of the water particles. The total wave force can be written as: