Design and economic analysis assessment of multi-use hybrid offshore Wind and Wave energy systems The present thesis aims to develop a preliminary assessment of a hybrid wave and wind offshore energy system. At the starting point benchmark research of technologies related to floating offshore wind turbine (FWOT) and wave energy converter (WEC), was made to obtain main technical data concerning each functionality. Afterwards the paper's theme shifted on the preliminary dimensioning project. Two commercialized FWOT platforms was selected: Nautilus and Spiderfloat, and their original design was modelled to support a 10 MW size wind turbine, in addition a point absorber called Reference Model 3 (RM3) was selected as WEC devices to be implemented as a semi structural component of the FWOT platform.