The Baltic Sea is a semi-enclosed sea with nine states bordering the sea. It consists of eight sub-catchment areas (sub-basins) and numerous harbours. It is estimated that about 2000 sizeable ships are at sea at any time, making the number of ships one of the highest in Europe. These ships will undoubtedly generate underwater noise that potentially might be harmful for the Environment. The BIAS project was established in September 2012 to support a regional assessment of the underwater sound in the Baltic Sea. The project has five objectives. The first is to raise awareness among authorities and managers. The second is to establish a regional implementation. The third objective is to assess the level of underwater noise and to present the results as soundscape maps. The fourth objective is to establish regional standards and methodologies that will allow for cross-border handling of data and results and finally to implement regional tools for handling of underwater sound.