PURPOSE: To reinforce a lever and enhance a cleaning power by installing an arch-shaped blade having projected and recessed parts on the surface to a lever with a brim which connects both ends with a sphere joint and constitutes a truss structural body radially along its axis and increasing the surface area.

CONSTITUTION: An arch-shaped blade 40 having projected and recessed part on the surface is radially installed to a pipe 12 which houses a tension rod 14 inside and provides a disk-shaped brim (reinforcing material) outside radially along its axis, thereby forming a lever 10. Then, a large number of levers 10 are assembled in such a fashion that they constitute a complex which defines a sphere 20 as its vertex on the end, thereby forming an underwater truss structural body. The surface area is increased and a contact area per unit with a water current is increased while kinematic energy is decreased. This construction makes it possible to enhance a breakwater power.