In this paper, the influence of the spatial configuration of a wave energy device array upon total power output is investigated. Hydrodynamic interactions are computed using a method capable of producing the linear wave theory solution to arbitrary accuracy. The overall performance of devices with two different power take-off arrangements is maximised at one incident wave frequency and direction by altering the formation of the array. Minimisation of the power is also carried out in a third case in order to demonstrate potential array-related losses. The optimisation is applied using two different approaches in each case: the Parabolic Intersection (PI) method and a Genetic Algorithm (GA). The former is a heuristic technique that has been devised for this study to enable rapid array construction using only simple calculations. The latter is an existing method, applied here with a novel crossover operator. Although considerably more computational effort is required, superior results may be obtained using the GA compared to the PI method. All of the arrays are subsequently analysed under incident waves of different frequency and direction, the resulting behaviour explained in terms of certain geometrical features of the arrangements.