Wave energy is still considered to be an emerging industry, and one significant contribution that researchers are making is to find solutions that reduce costs. The National Renewable Energy Lab (NREL) and Sandia National Laboratory (SNL) have contributed to this by creating WEC-Sim, an open-source modeling toolbox, to assist with early design decisions related to the design of Wave Energy Converters (WECs). Previously, studies involving WEC-Sim have focused on single WEC modeling. In this paper, we will conduct a validation study to investigate the accuracy and ability of WEC-Sim to model arrays of WECs. The results from the WEC-Sim array simulations are compared to those from an existing experimental study. In addition, the array model is used to investigate the interaction between the WECs in the array and the influence of array spacing on the WEC hydrodynamic performance.