First launched in June 1935, the Type II were the first U-boats commissioned in German yards after the repudiation of the Versailles Treaty. Unknown to other nations at that time, Germany had already begun construction for 12 new Type II U-boats as early as 1934. It was not until the signing of the Anglo-German Naval Agreement in February 1935 that construction began to be undertaken publicly. By June 15 1935, the first class of the Type II was launched.Small and cramped, the Type II were coastal boats intended principally for training, but because of the shortage of available boats, they were later relegated to war duties. With a crew of 25, the boats had limited range and carried enough provisions for three to four weeks, but frequently returned to port after expending their supply of torpedoes. Due to their small size and heavy rolling on the sea, the Type IIs quickly earned the nickname “Dugout Canoes”. Although of limited use in the open ocean, some remarkable successes were accomplished early in the war by U-boat aces such as Otto Kretschmer. The Type II also earned the respect and admiration of the crew due to its high maneuverability, rapid diving time and durability. Later in the war, due to the ever increasing need for training new crews, all Type II U-boats were withdrawn from combat duties and assigned to full-time training. A total of 50 Type II U-boats were built during the war. There are four variants, Type IIA, IIB, IIC and IID. The Type IIC was a further lengthened version of the Type IIB with an additional two compartments inserted amidships to accomodate improved radio room facilities and a second periscope. The additional diesel tanks beneath the control room was further enlarged, extending the range to 1,900 nautical miles at 12 knots.