Model predictive control (MPC) has proven its effectiveness in improving the energy capture efficiency of wave energy converters (WECs) under physical constraints. Further application of MPC requires to speed up its online computation for an industrial controller. To this end, the rollout-based MPC (RMPC) for WECs has been developed. The idea of rollout is to decouple the optimization horizon and the prediction horizon, so as to achieve long-horizon performance with short-horizon optimization. In this paper, the RMPC that has previously only been validated by simulation is further put through wave tank testing. The experimental device is a realistic two-body, taut-moored point absorber prototype. The RMPC is based on a simplified model of the device and implemented in real time with wave force estimation and prediction. Experiment results confirm RMPC’s energy efficiency as well as constraint satisfaction, so its computational advantage against conventional MPC is highlighted.