The modelling of nonlinear viscous effects for a wave energy converter (WEC) under control systems represents a difficult task. The control system aims to maximize the power capture of WECs. Consequently, large velocities of these devices observe. In addition, the linear potential theory is unable to show a realistic prediction of power production by neglecting viscous effects. A common way of modelling the viscous drag force of WECs is based on the viscous term of the Morison equation. In the literature, this approach shows that drag coefficient has a high variability that depends mainly on the relative velocity of the device. In the paper, two models analyze the nonlinear viscous effects on three cylindrical point absorbers. They have different diameter (D) to draft (T) ratios and are controlled by latching control. The first model approaches the viscous force according to the Morison equation. The second model is a heuristic model proposed by the present study. This new approach calculates the viscous force based on two parameters. Computational fluid dynamics (CFD) evaluates the fidelity of both models and the power production of the three-point absorbers. The proposed model shows good concordance with the CFD results at low and high velocities of point absorbers. The power production of the three-point absorbers controlled by latching shows that the power conversion increase is proportional to the D/T ratio.