This document compares two methods of parameterizing wave orbital motion - Isobe & Horikawa (IH) and Ruessink et al. (RUE) - in long-term coastal morphology models spanning timescales from milliseconds to centuries. The IH method leads to overestimated sediment transport, excessive morphological diffusion, and a lack of channels and erosion of flats in model results. The RUE method produces hydrodynamics and sediment transport more consistent with field measurements, resulting in modelled morphology that more closely matches natural coastal systems with better-developed channels and less diffusive features. Overall, the RUE parameterization provides substantial improvements over IH for modelling long-term coastal evolution.