This paper considers the process of modelling sediment transport and morphological change in the Pentland Firth and Orkney Waters using coastal area models. This region is atypical of regions commonly modelled using such techniques: it is high energy with limited and highly variable regions of mobile sediment. This causes challenges with regards both model capability and availability of data. Computational time restrictions for fully coupled modelling solutions should also be recognised which limits practical duration of simulation. Impacts to modelled bed level change over test periods are noted for both wave and tidal energy extraction scenarios. In both cases the magnitude of difference is equal to the magnitude of the change itself, however, lack of data and poor validation of the morphological modelling for the wave energy test case means confidence is low in these results. Based on the difficulties faced in conducting these modelling exercises and the high cost of additional data collection, it is recommended that regulators take a pragmatic approach when requiring such modelling for environmental impact assessments at some locations where changes to morphodynamics are unlikely to be critical to key receptors. Other approaches such as conceptual modelling or consideration of bed shear stresses could be undertaken rather than fully coupled morphodynamic modelling.