Tamrin
Perforated breakwater type is a type which rely on wave attenuation when reducing the wave height, This type becoming the new type that can be developed for friendly breakwater. The efficiency of this breakwater can be measured by counting Transmission coefficient (KT).The greater of transmission coefficient, more affective the breakwater. According to the test results and some analysed non dimensional relation parameter obtained the fact that transmission coefficient from this Perforated Concrete Block Breakwater (PCBB) is very determined by holes diameter on the surface and the wave length is very influential to minimum weight requirement of perforated block breakwater.