Operations and Maintenance (O&M) accounts for a significant portion of the overall lifetime cost of an offshore renewable energy development. O&M simulation tools can help to identify critical components in the design, estimate operational expenditure to improve cost of energy calculations, and help to optimise logistical strategies. To date, most O&M simulation tools have focussed on offshore renewable energy projects with one type of device. Complexity is increased if a device is a hybrid of different electricity generating systems. This paper explores the methodology of taking an existing O&M tool centred on wave energy devices and modifying it to model a farm of floating wind-wave hybrid devices. Initial results are discussed, including quantifying the impact that the ‘harbour effect’ has on O&M, whereby the significant wave height behind the platform is reduced, allowing increased accessibility. The O&M tool produced as a part of this work will be made publicly available under the Ocean Energy Scale Up Alliance.