Membranes made of materials such as reinforced rubber, geotextile fibres and plastics are conventionally used as temporary breakwaters. These membranes are lightweight, easily deployable, reusable and have minimum impact on key coastal processes. Recent advances in wave-energy converters (WEC) explore the use of piezoelectric material in floating membranes to extract wave energy from wide-range of frequencies. Similar innovations in floating photovoltaics (FPV) include thin-film amorphous panels which can potentially survive in harsh wave-conditions and have improved efficiency due to convective cooling by the surrounding water and undisturbed access to solar irradiance. Therefore, there is a need to develop methods and tools for design and analysis of structures analogous to floating membranes for diverse applications in the offshore environment. This manuscript presents a finite-element model for simulating the multi-physics fluid-structure interaction problem. The model captures for elastic response of the membrane and viscous dissipation of the wave-energy by the membrane. The membrane is exposed to realistic local wave conditions. The manuscript also studies the variation of membrane response with its material properties, such as density, and design properties such as tension, mooring conditions and number of joints.