At about 05:00 on 16 October, "U-353" was proceeding at full speed on the surface in total darkness. The U-boat saw the shadows of ships all around, the nearest about five miles away. This ship, the corvette detected the U-boat by radar, promptly closed the range and opened fire with her guns. "U-353" dived to and was attacked with depth charges, sustaining minor damage. The attack lasted for an hour before the corvette withdrew. An hour later the U-boat surfaced, and set a course to intercept the convoy.