From 1955, the West German Bundesmarine was allowed to have a small navy. Initially two sunken Type XXIIIs and a Type XXI were raised and repaired. In the 1960s, West Germany re-entered the submarine business. Because Germany was initially restricted to a 450 tonne displacement limit, the Bundesmarine focused on small coastal submarines to protect against the Soviet threat in the Baltic Sea. The Germans sought to use advanced technologies to offset the small displacement, such as amagnetic