This paper presents a recent numerical study conducted by researchers at the National Renewable Energy Laboratory on a point absorber wave energy conversion (WEC) system using a Reynolds-averaged Navier–Stokes (RANS)-based Computational Fluid Dynamics (CFD) method. The device we studied was a two-body floating-point absorber (FPA) that operates predominantly in heave and generates energy from the relative motion between the two bodies. We performed a series of numerical simulation to analyze the hydrodynamic response and the power absorption performance of the system in regular waves. Overall, it was successful to use the RANS method to model the complex hydrodynamics interaction of the FPA system. We demonstrated the significance of the nonlinear effects, including viscous damping and wave overtopping. The study showed that the nonlinear effects could significantly decrease the power output and the motion of the FPA system, particularly in larger waves.