The correct representation of set-down beneath wave groups in random wave harbour modelling

A device to compensate for set-down beneath wave groups in long crested random wave models has been developed and tested with satisfactory results. It is found that, generally, set-down compensation reduces the amount of long period energy in physical models. The works described in this report also shows how extremes of paddle movement become non-Gaussian when set-down compensation is employed with longer paddle strokes being required. Therefore, further research is also needed to enable extremes to be estimated so that the new wave-maker can be design with sufficient stroke to be capable of set-down compensation.