'Eismeer' was a U-boat operation intended to strengthen the 'Trutz' (ii) wolfpack (July 1944).

As they were on passage to reach the position of the 'Trutz' (ii) wolfpack, these U-boats came under severe British air attack. Oberleutnant Johann de Buhr’s U-347 was sunk by a Consolidated Liberator four-engined long-range maritime reconnaissance bomber of the RAF’s No. 86 Squadron and Kapitänleutnant Hans Seidel’s U-361 by a Consolidated Catalina twin-engined flying boat of the RAF’s No. 210 Squadron on 17 July; Kapitänleutnant Heinz Schwassmann’s U-742 was sunk on the following day by a Catalina of No. 210 Squadron that had to make an emergency landing because of damage suffered from its target’s anti-aircraft fire; and on 19 July U-968 was damaged by a Liberator of No. 86 Squadron, U-716 by a Liberator of the RAF’s No. 59 Squadron and U-387 by a Short Sunderland four-engined flying boat of the RAF’s No. 330 Squadron.