Ship motion forecasting systems and methods are described herein that can enable accurate real-time forecasting of ocean waves and resultant ship motions. Such systems and methods can be used to improve the efficiency and safety of a variety of ship operations, including the moving of cargo between ships at sea. In general, the systems and methods transmit radar signals from multiple radars, and those radar signals from the multiple radars are reflected off the surface of a body of water. The reflected radar signals are received, and radar data is generated from the received radar signals. The radar data is used to generate ocean wave components, which represent the amplitude and phase of a multitude of individual waves that together can describe the surface of the ocean. These ocean wave components are then used generate ship motion forecasts, which can then be presented to one or more users.