In this report the reader is oriented about the activities in underwatercommunication (uw-comm) at FOI (The Swedish Defence Research Agency) during 2011. The R&Dproject can be divided in three subprojects: UAN, RACUN and the construction of an uw-modem, which each are described under separate chapters. UAN is an international EU-project where the focus is on underwater networks for protection of critical infrastructure. The participation by FOI has mainly concerned propagation modeling and uw-communication. The RACUN-project is also international, but is an EDAproject and therefore has its main focus on military applications, in this case also an underwater network for naval task force operations. The purpose of the construction of an uw-modem is to obtain an experimental equipment for the navy for evaluating the usefulness of uw- communication, and for further development of the technique by FOI.