Knight’s Cross awarded for the successes achieved by him and his boat on all fronts. In the Norwegian campaign he sunk a freighter with 3000 GRT. On the night of 27/28.05.1940 he sunk the French destroyer “Sirocco” and a tanker with 1000 GRT. As the deputy commander of the 3. Schnellbootsflottille he achieved a notable success on 07.03.1941 near Great Yarmouth / Lowestoft. In three attack runs he sank two destroyers, two freighters with 5700 GRT and a tanker with 8000 GRT. Later on, in actions against the Soviets, he destroyed two armed Soviet freighters with 3577 GRT on 22.06.1941, and two days later the Soviet submarine S 3. On 27.06.1941 his and three other boats engaged with 7 Soviet destroyers and 1 torpedo boat. In a half hour fight he and his ships sunk 2 of these destroyers and the torpedo boat.
Oakleaves achieved due to further successes as the commander of S-56. Sank a Soviet patrol vessel on 18.08.1941. Sank a British patrol vessel in the Mediterranean on 07.05.1942. Sank another British patrol vessel and a submarine chaser on 10.05.1942. Torpedoed and severely damaged the British cruiser “Newcastle” on 14.06.1942. Destroyed a number of British ships as they attempted to flee the port of Tobruk when it fell on 21.06.1942 (3 small ships with 350 GRT, 4 barges, 1 freighter with 5000 GRT that had already been damaged by the Luftwaffe, 1 steamship with 6810 GRT, 1 large and 2 smaller landing craft).