As for bulk carriers and tankers it is important to calculate added resistance in waves in a ballasted condition with accuracy,because they are operated in ballasted conditions for half of their operation time. However, it is difficult to estimate the resistance with accuracy by the numerical calculation since wave making phenomena in a ballasted condition are a complex phenomena due to emersion of the bulbous bow.In this paper, we examine the adaptability of the hybrid method to the estimation of added resistance for the ballasted condition,which is practically corrected the added resistance in waves using tank tests. The comparison between calculation and tank test are presented here. Then we investigate the effect of trim which features the ballasted condition, and the effect of draft and frequency as well. Thereafter the influence of the present method on decrease of ship speed in actual seas is evaluated by contrast that derived from the tank tests.
