In the middle of summer 1944 German submarines arrived to Gulf of Finland. These boats were of type VII C. At first three boats U 481, U 748 and U 1193 arrived to Tallinn in the end of June. Within a month seven more boats (U 242, U 250, U 348, U 370, U 475, U 479 and U 679) arrived and in August even three more (U 717, U 745 and U 1001). German submarine headquarters was located in Kotka under command of one of the most decorated submarine commanders, Fregattenkapitän Albrecht Brandi. The submarine commanders were in totally different operational environment as usually. Instead of large, deep sea areas they now operated in confined, shallow waters infested with mines and light antisubmarine vessels. The operational areas of German boats were east from the Huovari-Narvi-Seiskari line and Narva Bay. The patrols lasted usually two days and no more than four boats were on patrol at the same time.
The Finnish Navy gave pilots to German boats. They were officers who had much experience in sailing these waters. One of them was my grandfather Lt. Tauno Paukku.
The German submariners did not found worthy targets for their torpedoes and perhaps flustrated tried to sink some of the 60-ton wooden submarine chasers (MO-boats). U 679 approached Bay of Vyborg on 14.7. but was derected from Ruonti island while still far away. Small units attacked immediately. The commander dared not to dive in so shallow waters and opened fire with light weapons. MTB TK 57 fired a torpedo that passed just ahead of U 679. A gun hit from a MO-boat damaged the tower of U 679 with loss of three men. The second torpedo of TK 57 also missed, and U 679 was saved by Finnish battery in Ristniemi that chased Soviet units away.
U 475 attacked on 18.7. with two torpedoes MO 304 that lost its whole bow, but was towed to harbour. On 28.7. U 370 was attacked by depth charges and responded with torpedoes. The attacking MO 107 lost its bow, but also this boat was towed to harbour.
On 30.7. the German submarine U 250 was lost. The boat sunk with one electric torpedo MO 105, but the following depth charge attacks in 25-30 meter deep water ripped open the engine room top. The commander and five other men escaped from the tower and were captured. The boat was raised by Soviets during the following weeks, with some secrets like T5 "Zaunkönig" acoustic torpedo and Enigma cryptographic machine.
German submarines moved to Narva Bay area after the loss of U 250. They managed to sunk some light vessels, but were often attacked by light naval units and IL-2 ground attack planes. German submarines lost their bases on the Finnish side on 6.9. and on the Estonian side on 20.9. After this they operated time to time in Gulf of Finland and Gulf of Bothnia till the end of 1944.
