The present study is focused on assessing the performance of a two-body heaving wave energy converter (WEC) connected to a compressible hydraulic power take-off (PTO) for an approximately 20-year horizon based on the temporal and spatial characteristics of the wave climate at eight selected locations in the Persian Gulf. The variations of the annual, seasonal and monthly mean absorbed, mechanical and electrical power of the selected WEC are presented based on the ERA5 hourly resolution reanalysis wave data set and power matrix of the device. Besides the expected output power, the capture width ratio and the capacity factor are evaluated as well. The hydrodynamic characteristics of the selected WEC are studied in the frequency and time domains. The time-domain modeling relies on the weakly nonlinear potential flow, which considers the instantaneous water surface elevation in water-body interactions to obtain more accurate nonlinear hydrodynamic forces. According to the obtained results in the studied locations, it is concluded that the dominant wave direction is northwest and possible conditions mainly related to events with peak periods between 2.5 and 5 s and significant wave heights up to 1 m. Moreover, based on the overall averaging and from the seasonal view in most locations, the maximum and the minimum mean output power occurs in winter and fall, respectively. The lowest monthly mean output power occurs in August, while the most energetic months are January and February.