The objective of this work is to assess the synergy of the marine resources in the vicinity of several European offshore sites, in order to analyze the viability of the combined wind-wave renewable projects. The reference sites considered for evaluation are located in the vicinity of the European coasts, being already taken into account for various marine projects. As a first step, based on the dataset provided by the European Center for Medium-Range Weather Forecasts for the 10-year interval 2005–2014, it was possible to analyze the joint seasonal distribution of the offshore resources. In the second part of the paper, based on the technical characteristics of various offshore wind turbines and wave energy converters, it was possible to identify the performances of some systems for wind and wave energy conversion. Finally, it can be also highlighted that the results presented in the present work can be considered interesting and useful, since they provide some insights regarding the potential of some operational European sites to support colocated wind-wave projects.