Experiments to study nonlinear waves are described. Sums of either four or two sine waves with different frequencies were used to drive a wave generator. The waves that were generated contained the nonlinear Volterra interaction frequencies that would be expected. Third-order effects were greater than second-order effects. Fourth and higher-order effects were small. The nonlinear interactions that resulted from the sum of two sine waves were compared with a model for eight different combinations of input amplitudes of two different pairs of frequencies. The agreement of the model with the measurements was poor except perhaps for the last three experiments. Some non-Stokes-like high waveforms were measured. A possible explanation for part of the poor results is the reflections from the waves breaking on the beach at the down tank end.
Refined experiments that could be done are described. Some possible areas for future research are suggested.