It seems that all the boats I see on the bay and lake leave a wake that's the same shape. The best nonmathematical explanation is that the phenomenon arises from the physical properties of water.
Water waves are fundamentally different from sound waves, for example.
Sound waves all travel at the same speed regardless of their length, Milewski explained. If they didn't, speech would sound like gobbledygook because the different wavelengths of sound in our voices wouldn't arrive at our ears at the same instant. Water depth and wave length. Water waves only create movement below the surface to a depth equal to the wave's length. So a boat moving over very shallow water creates waves that interact with the bottom, killing the effect.