In fact, as long as the water is deeper than the wave base, wave speed is inversely proportional to its frequency.
事实上, 只要水比波底深,波速就与其频率成反比。
英语百科
Wave base
The wave base, in physical oceanography, is the maximum depth at which a water wave's passage causes significant water motion. For water depths deeper than the wave base, bottom sediments and the seafloor are no longer stirred by the wave motion above.