The hydrodynamic forces acting on a model of a high-speed craft fixed by a load cell on a towing carriage are systematically measured for various trim angles, sinkage and forward speed. These data is found to be useful to know the hydrodynamic characteristics of the shape of a high-speed craft. A simulation method for predicting the attitude and speed of the craft for a given thrust force using the measured hydrodynamics forces is proposed. The simulation results demonstrate the effect of the hight of the centre of gravity and the angle of a propeller shaft on the speed of the craft. Measurements of wave exciting forces acting on the model craft moving in regular head waves are carried out. The results show a significant dependency of the pitch exciting moment on the sinkage of it.