Marine energies have a significant potential as an alternative to fossil fuels. However, the current high cost of the technology or the intermittency of the resources are often cited as a barrier to their large-scale development. The combined harnessing of different ocean resources in the same area can contribute to overcoming these issues. This work deals, in particular, with co-located wind and wave farms. With a currently operational wind farm as a reference, different co-located layouts are proposed and their impact on the Levelised Cost of Energy (LCOE) is analysed. A third-generation spectral wave model (SWAN) and real wave climate data are used. First, the combined use of the resource is characterised – energy yield per unit area, smoothing of power output, average power output and its seasonal variability. Second, a number of co-located layouts and the baseline (wind only) farm are compared in economic terms. Finally, conclusions are drawn on the potential cost reductions in co-located farms. We find that the energy cost is reduced by more than 50% relative to stand-alone wave farms. These results confirm the interest of combining wave and wind energy through co-located farms for the purpose of enhancing the economic viability of wave energy.