Navigation Condition Effect on Ship Motion in some Sea State

According to analyzing the identity of ocean wave, theory of wave energy spectrum was applied to compute the curve of wave elevation vs. time in some sea state. Based on ship motion equations, ship motion was acquired by the simulation software of the of ship strip theory in some situation. How different navigation conditions effect on ship motion is researched in some sea state. The results show the change of degree of abaft the beam badly influenced the amplitude and periods of pitch, it also influenced periods of heave and amplitude of roll. The change of ship speed influenced the amplitude and periods of pitch, it also influenced periods of heave and roll.