For this configuration the results for regular waves are presented in Fig. 11 together with the ones for the single fixed FB case for comparison purposes. In Fig. 11 the effect of B/L (d/L) on the performance of the FB is presented. For B/L greater than 0.275, the performance of the heave motion FB can be considered satisfactory since Ct is less than 0.5. The heave motion FB also performs efficiently under the forcing of short period waves in intermediate and deep waters (d/L > 0.275). The transmission coefficient reaches the values of 0.41 and 0.46 for the 0.2 and 0.3m wave height, respectively.