23 Nov 1940
While attacking convoy OB-244 (4 ships sunk) the boat hit an unknown object (probably accidentally rammed by a convoy vessel) and was seriously damaged and had to abort to France for 50 days of repairs. (Sources: Blair, vol 1, page 208)

27 Jun 1941
Having torpedoed 2 ships from convoy SL-78 the boat was depth charged for 11 hours but escaped by going very deep - down to 654 feet, below the range of the British depth charges. (Sources: Blair, vol 1, page 302)

12 Aug 1941
The boat was attacked by convoy escorts near Portugal. All in all 126 depth charges were dropped, including 30 "close by" as reported by the Germans. The boat suffered some medium damages and headed for France, having been at sea for over 60 days when this attack took place. (Sources: Blair, vol 1, page 336)

21 Oct 1941
After damaging the British Armed Merchant Cruiser HMS Aurania, U-123 took one seaman of this ship on board as a prisoner. In the evening the boat was attacked by a British Sunderland aircraft with two bombs. U-123 suffered slight damage.

16 Jan 1942
At 00.01 hours, the boat was surprised and attacked by an aircraft off New York. Four bombs were dropped that missed and U-123 escaped undamaged by crash-diving. (Sources: KTB U-123)

19 Jan 1942
Kosmos II tried to ram the surfaced U-123 off Oregon Inlet. The U-boat was in shallow water, without any torpedoes left and one of the diesel engines out of order. The Germans managed to get the engine running when the ship was only 75 metres away and slowly out-distanced her at full speed.

27 Mar 1942
After being torpedoed by U-123 the American Q-ship USS Atik (AK 101) surprised and attacked the boat off the US East coast. In the action one man from U-123 was fatally wounded and the Q-ship was sunk with all hands. [Fähnrich zur See Rudi Holzer] (Sources: KTB U-123)

2 Apr 1942
During the attack on Liebre the boat was forced to dive by a patrol vessel and attacked with a depth charge in shallow waters. U-123 only escaped undamaged because no other attacks followed. (Sources: KTB U-123)

11 Apr 1942
After sinking Gulfamerica the boat was located in shallow waters by an aircraft which directed a destroyer to the position. At 09.17 hours six depth charges were dropped on U-123 moving over the bottom at a depth of 20 m and badly damaged her. The boat played "dead man" and despite air bubbles escaping from damaged valves no more depth charges were dropped by the destroyer which left after one hour. Most of the damages could be repaired by the crew and the boat continued the patrol. (Sources: KTB U-123)

25 Aug 1943
Depth charged off Cape Finisterre by allied escort vessels. Date is approximate. (Sources: Blair, vol 2, page 406)

7 Nov 1943
At 09.44 hours, the inbound U-boat was attacked by a Mosquito aircraft (RAF Sqdn 618, pilot F/O Al Bonnett RCAF) in the Bay of Biscay. This was the first attack by a "TseTse" Mosquito (equipped with a 57mm cannon) and the hit scored on the conning tower killed 1 man, wounded 2 others and left the U-boat unable to dive due to a hole of 18 x 6,5cm. [Bootsmaat Günther Struve] (Sources: Ritschel)

11 recorded attacks on this boat.