Floating pier BW400 (BW300), is a wave attenuator and high-stability mooring quay able to protect partially sheltered docks. This pier consists of a system of modular elements interconnected by semi-elastic joints. The modules are floating structures made of reinforced concrete conglomerates. Inside, a core of polystyrene foam make them light and unsinkable. Concrete is obtained from a mixture of pozzolanic or blast furnace cements and is therefore suitable to the marine environment. Selected aggregates assure a high-quality concrete.