Space-time evolution of random wave groups with high waves based on the quasi-determinism theory

In this paper, the space-time evolution of ocean wave groups when a large wave occurs is studied. The theoretical wave profiles have been firstly investigated by applying Boccotti's quasi-determinism (QD) theory up to second-order. It is shown that the theory can describe the wave groups either in the time domain at any fixed point, or in the space domain at any fixed instant of time. Validation of the theory is then proposed by considering laboratory generated time series representing the evolution of the famous New Year wave at the Draupner platform. It has been concluded that the evolution of the largest wave in a sea state may be predicted well by the theoretical nonlinear profiles of the QD theory.