The oscillating wave surge converter (OWSC) type devices (e.g., an Oyster wave energy converter) generate electric power via rotating motion about the bottom of the device. This type of wave energy converters have a wide power absorption bandwidth which enables the electricity generation at a wide range of wave frequencies. The power produced by the OWSCs could be maximised by configuring individual devices within an array. This paper examines the power production performance of multiple OWSCs in an array under regular, uni-directional irregular wave and multi-directional sea using the industry standard hydrodynamic software WAMIT. The performance of the OWSC array is represented as q-factor, which is a quantity defined as the ratio of the average total power produced in an array to the power produced by an individual OWSC. The results show that the OWSCs arranged in an array would produce both constructive and destructive interferences depending on the wave directions and frequencies. Further, the spreading function, the resonance bandwidth and the optimal spacing between the devices are shown to affect the performance of the OWSC significantly. The results provide an enhanced understanding of the behaviour and performance of the OWSCs when arranged in an array of different configurations.