As waves enter the surf-zone, the wave spectra undergo drastic transformations because of depth-induced breaking and triad interactions. Any arbitrary spectrum will converge towards a smooth, universal shape in which initially higher harmonic peaks emerge that disappear as wave propagate further into the surf-zone. The current formulation of triad interactions in the spectral wave model SWAN (LTA), is not capable of converging spectra towards a universal shape and removing the higher harmonic peaks. A newer formulation for triad-interactions, called the DCTA, was therefore published in 2006 and this formulation was further developed in this M.Sc. thesis. After an initial improvement of the conceptual formulation, the DCTA has been validated, calibrated and verified with a series of laboratory and field measurements. The formulation of the DCTA and the results of the quantification are presented.