HMS Ocelot, Chatham dockyard, 9 June 2012 2. The Oberons were diesel electric boats. Two Admiraly 3680hp diesels each drove a generator which powered a 3000hp electric motor. Batteries powered the motors when the boat was submerged. The Oberons were faster underwater (17 knots) than surfaced (12 knots). They had six 21 inch bow tubes and two in the stern. The could launch mines as well as torpedoes. Their complement was 7 officers and 62 ratings.