摘要:Since catamarans can reduce wave-making resistance by making the hulls slender, the ships can be easily speed up at high-speed.However, high-speed catamarans are significantly affected by the sea state because of its light structures and high cruising speed.Therefore, it can be said that it is important for high-speed catamarans to know the seakeeping performances of the ship preliminary design stage. Although linear strip methods are widely used to estimate seakeeping performances of ships, it is thought that those prediction methods are not in work for high-speed catamarans because the ships have unique hull shapes and high forward speed.In the present study, since it was found that ship motions of the high-speed catamarans which operated in waves were significantly influenced by hydrodynamic lift force acting on hulls especially in high advanced speed, a prediction method for wave-induced ship motions, which includes hydrodynamic forces originated from lift force, was developed. The comparison between the predicted and experimental results demonstrates that the proposed method has enough accuracy for estimating ship motions in head seas.