Extremes of second order wave quantities

A general theory derived previously for the prediction of extremes of certain class of non-linear variables, has been shown to be applicable to a general quadratic process. In this report the technique has been applied to two cases of particular interest. One is the prediction of extreme values of set-down in random seas. The other is the prediction of extreme values of paddle movement in physical models of harbours where compensation for set-down is necessary at the wave-maker to avoid the generation of spurious long waves. The prediction of extreme paddle movements with set-down compensation is needed for proper design of the wave generator.