On 21 October moved into the entrance of the river and encountered widespread RCN patrols. The submarine's captain, Hans-Joachim Schwantke, attempted to attack convoy SQ-43 off Gaspé, but was spotted and repulsed by the convoy's escorts. It was stated that six depth charges from the "Bangor"-class minesweeper knocked out the U-boat's lights, blew the battery circuit breaker and activated a torpedo in one of the sub's stern tubes. Captain Schwantke pushed his sub down to to avoid what he thought was a co-ordinated attack. The submarine was damaged but escaped the river.