 After leaving Marvika at Kristiansand in Norway, "U-961" headed directly for the North Atlantic Ocean, the main battleground of the Battle of the Atlantic.By 1944 however, the region had become a U-boat graveyard, as drastic improvements in submarine detection and destruction had been made, both by surface shipping and by allied aircraft.The patrol lasted just seven days, ending during an attack on convoy JW 58 north of the Faroe Islands on 29 March.