The performance assessment of industrial marine energy converters involves the integrated treatment of their hydrodynamic design and the optimization of their device hulls. Nowadays, such tasks require extensive experimental work and simulation plans, consuming considerable resources and time. In this comprehensive review of integrated approaches to numerical and experimental testing, the advantages and disadvantages of existing tools, from full-scale prototype and wave tank models to Computational Fluid Dynamics (CFD) and potential flow simulations, are all analysed. Likewise, current challenges such as experimental scale effects, numerical viscosity, and turbulence treatment are all studied. The novelty of this research is an integrated approach that employs experimental wave tank tests to validate a numerical wave tank model based on CFD that serves to calibrate a fast potential flow solver with Morison's correction terms. The model allows running, on tight resources, the necessary simulation for the design and optimisation of marine energy converters under multiple sea state conditions. Given the operating regimes of conventional marine energy converters, the results show that the influence of turbulence may be small, due to the unsteady nature of the oscillatory boundary layer flows.