An experimental study on the improvement for the problem of wave transmission in slightly submerged breakwaters is carried out in the present paper. The breakwater shape, effect of the porosity, water depth regarding the breakwater crest height and, dynamic stable deformed breakwater were examined as parameters. During the experiments, porosity was varied between 0.57-0.34, breakwater crest height to water depth ratio changed from I to 0.83. The similarity between a longshore bar and a dynamic stable submerged breakwater was also studied in one set of the experiments. Results indicated that a dynamic stable breakwater similar to a longshore bar resulted in better energy dissipation and the best transmission coefficient values determined between 0.3-0.1 in the mentioned condition.