Wave energy Computer simulation showing the energy flow of ocean waves moving through current eddies The simulation shows the result of ray trajectories travelling at three different speeds through a region with current eddies The eddies act as an optic lens and cause refraction of the waves resulting in areas of concentrated energy This is visible as a pattern of twisting and branching known as caustics It is believed that caustics resulting from strong ocean eddies interacting with wave action may be the cause of giant ocean waves known as freak or rogue waves Such waves have been reported to reach as high as metres and have been blamed for the disappearance of some ships Simulation created by Eric Heller Professor of Physics at Harvard University Massachusetts USA