SA-51 is one of two small Spanish submarines built in 1964. They had a crew of five men, carried two torpedo tubes, and could operate for up to a week. SA-51 is now preserved and mounted on a traffic island in Barcelona - she is believed to be owned by the Cosmo Caixa Science Museum which is nearby. Her sister, SA-52, is apparently on display in Cartagena, however I haven't been there.
