A 25ft class fishing leisure boat is developed, and the resistance performances are investigated by a model test in a high-speed circulating water channel. The design speed of the developed ship is 25 knots using a 150 ps outboard engine. A catamanan type hull form using a planing section is adopted considering the Froude number and large deck area. The effect of a center body attached on the bottom of the cross deck is studied under various conditions. Wave patterns are observed to make clear the relationship between the resistance performance and the wave characteristics. The results show that the shape of the center body and the position of the chine line can have a strong effect on the resistance performance in a certain velocity range.