Germany's first post-World War 2 submarine became the coastal patrol-minded "Type 201" (detailed elsewhere on this site). While twelve were planned for the class, just three were built when it was found that their anti-mine hulls were prone to fracturing under basic use. This led to short service lives for the group and the boats were out of service as soon as 1967. To shore up the deficiencies in the Type 201 design, the "Type 205" class was quickly drawn up using a basic single-layer, steel hull. Like the Type 201 boats, the new class was developed for shallow water work in and around the Baltic Sea with the primary enemy of the time being the Soviet Union. For the role, the boats were crewed by a modestly-sized complement and showcased compact dimensions.
All thirteen of the planned boats of the class were completed and three of the lot were eventually preserved once their days were over (the remaining boats were all stripped of their military usefulness and scrapped). Of the thirteen, eleven served with the West German Navy while two, Narhvalen (S320) and Nordkaperen (S321), were built for Denmark (both since scrapped). These were known locally as the "Narhvalen-class".
As built, the class displaced 412 tons (long) when surfaced and 450 tons when submerged. Length measured 145.3 feet with a beam of 15 feet and a draught of 12.5 feet. Power was from twin Mercedes-Benz V12 diesel units of 590 horsepower each coupled to a single BBC generator unit. There was also a single SSW electric motor in the mix and this outputting 1,500 horsepower to the single shaft. Surfaced ocean-going speeds could reach 10 knots with submerged speeds topping 17 knots. Range was out to 4,550 miles when heading at 4 knots. The hull was tested to depths of 330 feet (100 meters).
Aboard was a crew of 22 men (to include four officers). Armament was the typical array of 8 x 533mm (21") torpedo tubes and the boat had a built-in mine-carrying capability.
U-1 was launched on February 17th, 1967, commissioned on June 26th of that year, and operated until November 29th, 1991. She was beaten into service by U-4 which arrived on November 19th, 1962 (though only operating until August 1st, 1974). The last of the German boats became U-12, launched on September 10th, 1968, commissioned on January 14th, 1969 and decommissioned on June 21st, 2005. The class was notable enough to German navy history to see three of their number preserved as floating museums - these becoming U-9, U-10, and U-11.
The two boats built for the "Kongelige Danske Marine" (Danish Navy) operated from 1970 until 2004. Narhvalen was launched on September 10th, 1968, commissioned on February 27th, 1970 and decommissioned on October 16th, 2003. Nordkaperen followed when launched on December 18th, 1969, commissioned on December 22nd, 1970, and decommissioned on February 2nd, 2004.