[ijnfleetadmiral]

U-209 departed Brest on her 12th patrol on 16 October 1940. That evening, Small Merchant Destro (2,343 tons) and C2 Cargo Kendal Fish (6,446 tons) were sent to the bottom using the deck gun. Unfortunately, the seas grew rough after this, and the crew were unable to man the deck gun to sink any further ships. (In CO's opinion, "God forbid you boys get wet!")

C3 Cargo Henrico (7,909 tons) was sunk on 17 October, with C2 Cargo Carrier Pigeon (6,448 tons) sunk on 19 October. Two days later, C2 Cargo Oriental (6,452 tons) was sunk, with C3 Cargo Custer (7,951 tons) sunk the following day.

Another C3 Cargo (name unknown) was attacked with the last two torpedoes, one of which turned out to be a dud (the Satanic prophet Moe Hamhead was cursed to the very depths of the earth for this unfortunate occurrence), while the remaining one hit and destroyed the ship's engines, leaving her dead in the water, but not sinking. Due to the rough seas (the gunners again took berating from the CO for not wanting to get wet), U-209 was unable to finish this target off.

Returned to Brest on 24 October 1940, with 6 ships sunk for 37,549 tons. Upon return, OLzS Suckel was awarded the Diamonds to his Knight's Cross, and U-209 was subsequently transferred from 1st Flotilla to 7th Flotilla based out of St. Nazaire.