COMPUTATIONAL APPROACHThe mathematical model is based on a time-step solution of the system of coupled differential equations of motion. Vessel specific results from linear diffraction calculations, consisting of frequency dependent wave forces, added mass and damping are typically used to model the hydrodynamics. The impulse response method is then applied to determine the time domain response. Other elements such as rudders, propellers, mooring lines, fenders, thrusters, etc are modelled in time domain. Depending on the application, one of the available generic solvers is used to solve the equations of motions.