were also provided aft of the engines for the engine room crew. Cooking and sanitary facilities were basic, and in this environment long patrols were very arduous. Most Type IIs only saw operational service during the early years of the war, thereafter remaining in training bases. Six were stripped down to their hulls, transported by river and truck to Linz (on the Danube), and reassembled for use in the Black Sea against the Soviet Union. In contrast to other German submarine types, few Type IIs were lost. This reflects their use as training boats, although accidents accounted for several vessels. These boats were a first step towards re-armament, intended to provide Germany with experience in submarine construction and operation and lay the foundation for larger boats to build upon. Only one of these submarines survive; the prototype CV-707, renamed Vesikko by the Finnish Navy which later bought it. On 3 February 2008, The Telegraph reported that U-20 had been discovered by Selçuk Kolay (a Turkish marine engineer) in of water off the coast of the Turkish city of Zonguldak. According to the report, Kolay knows where U-23 and U-19 are, scuttled in deeper water near U-20. Comparison of Finnish Crichton-Vulcan CV-707(U2A) to German Type II Type IIA The Type IIA was a single hull, all welded boat with internal ballast tanks. Compared to the other variants, it had a smaller bridge and could carry the German G7a, G7e torpedoes as well as TM-type torpedo mines. There were separated net cutters in the bow. The net cutters were adopted from World War I boats but were quickly discontinued during World War II. Deutsche Werke AG of Kiel built six Type IIAs in 1934 and 1935. List of Type IIA submarines The prototype, built in Finland: Finnish submarine Vesikko Type IIB The Type IIB was a lengthened version of the Type IIA. Three additional compartments were inserted amidships which were fitted with additional diesel tanks beneath the control room. The range was increased to 1,800 nautical miles at 12 knots. Diving time was also improved to 30 seconds. Deutsche Werke AG of Kiel built four Type IIBs in 1935 and 1936; Germaniawerft of Kiel built fourteen in 1935 and 1936; and Flender Werke AG of Lübeck built two between 1938 and 1940. In total, twenty were built. List of Type IIB submarines There were 20 Type IIB submarines commissioned. Type IIC The