In the third set of experiments, a single fixed FB with an attached metal plate at the front part was tested. Christian (2000) andTolba (1998) experimentally tested FB with an attached metal plate at the middle of the submerged structure bottom. They concluded that the plate improves the efficiency of the structure, but not as much as in the case of FB with overall draught equal to that of the metal plate. The observed vortex generation in the front submerged part for the single fixed breakwater case (Fig. 7) lead to the idea to test the FB with the plate at the front part to reveal the impact of the position of the plate on the FB efficiency. The draught of the FB was 0.2m (dr/d = 1/10). The height of the iron plate was 0.2 m, leading to a local draught of 0.4m at the front face of the FB. The tested wave conditions were the same as in the single fixed FB case.