AN EXPERIMENT AT SEA ON THE REFLECTION OF THE WIND-WAVES

Before a reflecting wall, the wind waves strongly differ from the periodic waves. The nodes and the antinodes tend to disappear starting one wave length from the wall. The wave period, as a function of the distance from the wall, exhibits some negative discontinuities at the nodes. Those properties were predicted from an analysis of theoretical spectra and were confirmed by an experiment which employed 30 wave gauges at sea. The experiment revealed also a characteristic pressure-fall under the crests of the highest waves at the wall. The phenomenon was related to high water jets detected at the centers of the wave fronts.