Light cruiser HMS Effingham: Allocated to the Northern Patrol in the 12th Cruiser Sqn, then escorted North Atlantic convoys until the end of the year.
- Light cruiser HMS Ajax: HMS Ajax (Capt. C.H.L. Woodhouse, RN) intercepts the German merchant Carl Fritzen (6594 GRT) in the South Atlantic off the coast off Uruguay in position 34°19'S, 48°29'W. However before the ship can be captured she is scuttled by her crew.
Destroyer HMCS St. Laurent: HMCS St. Laurent (Lt. H.S. Rayner, RCN) picks up 89 survivors from the British merchant Titan that was torpedoed and sunk by German U-boat U-47 about 80 nautical miles south-west of Rockall in position 58°14'N, 15°50'W.
- Destroyer ORP Garland: The destroyers were attacked by Italian aircraft. Near misses caused boiler damage on Garland. She stopped and became an easy target. However, the Italian bombs missed the Polish ship. Garland was towed away by a British destroyer. Then the crew managed to repair one boiler and steam to Gibraltar for further repairs.
- Destroyer USS Greer: On 4 September 1941, USS Greer had been signalled by a British bomber, that a German U-boat was hiding in the vicinity. Greer found sound contact, and started to pursue the U-boat (U-652) from close range. The aircraft dropped 4 depth charges, and left the scene, leaving the two fighting ships. Soon after the U-boat fired a torpedo at the US warship, perhaps believing she dropped the four bombs. After this USS Greer went into attack, and a 2 hour battle followed, during which she dropped 19 depth charges, and the U-boat fired another torpedo, without results. President Roosevelt used this event in his campaign to convince the US to go to war, and the "undeclared war" between U-boats and US escorts escalated dramatically.
- Destroyer USS Cooper: USS Cooper arrived at Pearl Harbor.