The optimisation of a Numerical Wave Tank is proposed to accurately model regular waves superimposed on a uniform current velocity. ANSYS CFX 18.0 was used to develop a homogenous multiphase model with volume fractions to define the different phase regions. By applying CFX Expression Language at the inlet of the model, Stokes 2nd Order Theory was used to define the upstream wave characteristics. Horizontal and vertical velocity components, as well as surface elevation of the numerical model were compared against theoretical and experimental wave data for 3 different wave characteristics in 2 different depth tanks. The comparison highlighted the numerical homogeneity between the theoretical and experimental data. Therefore, this study has shown that the modelling procedure used can accurately replicate ocean wave-current conditions providing a potential substitute to experimental flume or tank testing.