This was a so-called 'special operation' patrol by the German submarine arm in the later stages of World War II.
At a time early in January 1945, the U-boat U-245 departed from a base in Norway, now the primary rearming, refuelling, maintenance and repair area for the remnants of the German submarine arm (following its loss of the superior bases the Germans had built in western France), to stage via the island of Heligoland in the North Sea. The boat then proceeded to the estuary of the Thames river, east of London, with the object of attacking Allied shipping. After encountering mines and strong currents in shallow water, the boat reached its designated operating area but there managed to sink only one ship, the 2,600-ton Dutch tanker Liseta. The boat then returned to Heligoland to prepare for a repeat mission.
In its second patrol of 'Brutus' (iii), U-245 departed on 9 April 1945 for the British coastal waters off East Anglia. Here, on 17 April off Harwich, U-245 found the TAM.147 convoy, and hit and sank two ships, the 4,900-ton British Filleigh and the 5,000-ton Norwegian Karmt. The weapons used were a pair of new and long-ranged acoustic-homing torpedoes. The boat also launched a G7es, another type of acoustic-homing torpedo, at an escorting British corvette, but this missed its target.
As the war ended, U-245 returned to Bergen in liberated Norway.