It is as though all the energy being carried by the water waves is converged at a single point - the point is known as the focal point. After passing through the focal point, the waves spread out through the water. Reflection of waves off of curved surfaces will be discussed in more detail in Unit 13 of The Physics Classroom . Refraction, or bending of the path of the waves, is accompanied by a change in speed and wavelength of the waves. The most significant property of water which would effect the speed of waves traveling through it is the depth of the water.
Water waves travel fastest when the medium is the deepest.
Thus, if water waves are passing from deep water into shallow water, they will slow down. So as water waves are transmitted from deep water into shallow water, the speed decreases, the wavelength decreases, and the direction changes. This boundary behavior of water waves can be observed in a ripple tank if the tank is partitioned into a deep and a shallow section. If a pane of glass placed in the bottom of the water, one part of the tank will be deep and the other part of the tank will be shallow. When traveling from deep water to shallow water, the waves are seen to bend in such a manner that they seem to be traveling more perpendicular to the surface.