Wave energy converters (WECs) have a strong potential to contribute to satisfy the increasing global energy demand. Developing e??cient, cost competitive and survivable WECs is the focus of research and development efforts from both industry and academia in recent decades, and has proven to be a challenging task. An essential development trajectory to an economically competitive WEC, requires early stage optimization and re nement of the device design and operation using numerical tools, before considering expensive physical prototype construction, deployment and experimentation. For the research and development of wave energy converters (WECs), numerical wave tanks (NWTs) provide an excellent numerical tool, enabling a cost-effective testbed for WEC experimentation, analysis and optimization.