The energy dissipation coefficient increases with decreasing wave period, revealing the increase of energy dissipation in short
period waves. Again this is due to the increasing vortex intensity, observed in the front submerged part of the breakwater,
with decreasing wavelength (Fig. 8). The Cd reaches values of 0.45–0.5 and 0.85–0.90 for the longest and shortest period,
respectively. This is mainly due to the fact that for shorter period waves, the FB moves vertically out of phase with the standing wave formed in front of the structure, while in longer period