Wave dynamics
From KayakWiki
Waves are one of the most basic of physical phenomena. Light and sound travel in waves and waves in water have many of the same properties as light and sound waves. Unless they meet some obstruction a water wave will travel in a straight line and will loose little energy as it travels. As a wave radiates out from a point source the energy will be dispersed over a larger area, in an ideal case falling off at 1/ r2 where r is the radius from the source.
When a wave encounters an obstruction such as an island or sand bar or beach it will be reflected, refracted, or diffracted. This action can change the wavelength and wave height as well as the direction the wave travels. In addition, if a wave train acts upon two or more different obstructions, the resulting wave pattern will be the result of constructive interference and destructive interference. This pattern can be fairly regular or appear almost random. Clapotis is the result.
A simple accurate model for a deep water wave is a sine curve but a more accurate model of shallow water wave is a trochoidal wave.
See also Wave velocity, Wavelength
