Large areas of the Greek coastline have been examined by divers, and the Greek authorities have an existing database of approximately 1000 shipwrecks in shallow water. Very little is known about sites in deeper water where conventional diving is impossible. The Greek-Norwegian Deepwater Archaeological Survey was a joint project of the Greek Department of Underwater Antiquities (EEA), the Norwegian University of Science and Technology (NTNU), the Norwegian Institute at Athens (NIA) and Promare. The main goal of the project was to test cost-effective remote sensing methods in order to locate marine cultural remains in depths below 50 meters. Several new shipwrecks were located, and the results of this survey constitute a new source for research activity and an effective tool for the Greek Ministry of Culture in its efforts to protect the underwater cultural heritage in the selected areas.