The weight of the armor block on the mound of the breakwater covered with wave-dissipating blocks might be smaller than that of the breakwater without wave-dissipating blocks, however the fit weight has not been studied so much. Therefore, the water velocity around the armor blocks and the damage rates of the armor blocks, of the breakwater covered with wave-dissipating blocks are studied in experiments and are compared with those of the breakwater without wave-dissipating blocks. Additionally, the diagram giving the fit weight of the armor block on the mound of the breakwater covered with wave-dissipating blocks for an allowable damage rate of 1% by using the Ns value is proposed.
