This chapter studies the social acceptance and socio-economic effects associated with the development of multi-use offshore platforms, using a theoretical Green&Blue concept off the Liuqiu Island as a relevant case study. The Green&Blue concept combines the generation of clean energy with the commercial use of biological ocean resources. Social acceptance of such development is evaluated based on a face-to-face survey together with in-depth interviews with local people and tourists who are currently or will be potentially affected by the offshore development. A choice experiment is used to assess the ecosystem services and non-market effects of the offshore development. The social cost-benefit analysis is adopted to synthesise both market and non-market effects. The study finds a generally high support for the offshore development among tourists. The concern mainly focuses on the uncertain environmental impacts and effects on the local fishery industry. Neither locals nor tourists view the energy hub which generates most income and jobs as a very attractive option. The offshore development concept shows a high environmental non-market benefit which amount to 618 million $NT. However, the high investment cost overweighs the positive GDP and environmental gain.