Accuracy of longitudinal-cut wave analysis technique and model size scale effect appearing on wave- and wave pattern-resistance are discussed. Making use of geosims of Series 60 hull, both standard and additional ITTC Cooperative Experiments are conducted in nine organizations of Japan. Varieties and trends of the resistance components ensued through measurements and analyses procedures are surveyed. Results are summarized as follows. Selection of truncation point is important for getting reliable results. Effect of difference of program code on analysis results is negligible among the present organizations. Model size scale effect is recognized on wave pattern resistance, but not on wavemaking resistance. Damping of wave amplitude for the actually propagating waves is stronger than the asymptotical estimation by the linear theory. The interference of ship waves and its boundary layer and wake is considered one of the most important factors in considering Reynolds number effect.