U-46 was ordered to patrol the coast of Sunderland, which had been chosen for the diversionary attack, but because of engine problems it was unable to leave port and U-47 was diverted to this task.
Ao U-46 ordenouselle patrullar a costa de Sunderland, que fora elixida para o ataque de distracción, pero debido a problemas no motor non puido deixar o porto e o U-47 foi desviado para realizar esta tarefa.