An example of refraction<span> is when </span>waves<span> approach a straight shoreline at an angle. The part of the </span>wave<span> crest closer to shore is in shallower water and moving slower than the part away from the shore in deeper water. The </span>wave<span> crest in deeper water catches up so that the </span>wave<span> crest tends to become parallel to the shore.</span>