The primary aim of the study was to investigate the optimal scaling of a simple generic wave absorber for a range of operation sites characterized by their level of incoming wave power, annually averaged. The first step is to to answer the simple question: " What is the optimal size of my device in a sea state characterized by a wave height and peak spectrum period? ". It is shown how to find the optimum scale starting from the power response operator of the reference device at unity scale. From this primary result, the method is extended to answer the same question but now considering an installation site with its own set of sea states given as a scatter diagram. In each case the answer could seem rather counterintuitive refering to the common practise in this matter.