On 6 Feb, 1940, the Hanonia was commissioned in the Kriegsmarine as Schiff 11/Ulm after conversion to an auxiliary minelayer was completed on the Stülckenwerft. On 9 Mar, 1940, Schiff 11 laid 144 mines and 146 explosive buoys off the Dutch coast, which had following results:
On 9 Mar, 1940, sunk Belgian motor fishing vessel Santa Godelieva (34 grt) west of Ostende. On 11 Mar, 1940, sunk Dutch steam merchant Amor (2325 grt) in 51°24N/02°09E. All 33 crew members survived. On 11 Mar, 1940, damaged Greek steam merchant Niritos (3854 grt) in 51°25N/01°45E. On 12 Mar, 1940, sunk French sailing vessel Rose Effeuillee (35 grt). On 15 Mar, 1940, sunk British steam merchant Melrose (1589 grt) in 51°21N/02°13E. On 15 Mar, 1940, sunk Dutch motor merchant Saba (397 grt) en route from Caen to Ijmuiden. On 17 Mar, 1940, sunk Dutch steam merchant Sint Annaland (2248 grt) in 51°24N/02°01E. On 18 Mar, 1940, sunk Italian steam merchant Tina Primo (4853 grt) in 51°20´43N/01°44´27E. 1 of 37 crew members was lost. On 20 Mar, 1940, damaged Dutch motor tanker Phobos (7412 grt) 5 miles east of North Galloper. On 8 Apr, 1940, sunk Greek steam merchant Okeania (4843 grt) in 51°16´48N/02°03´12E. 1 crew member was lost. On 12 Apr, 1940, sunk Dutch motor merchant Velocitas (197 grt) in 51°25N/01°50E. On 23 Apr, 1940, sunk British steam merchant Lolworth (1969 grt) in 51°22N/01°26E.
A total of 10 ships with 18.490 grt were sunk and two ships with 11.266 grt damaged.

On 2 Apr, 1940, the vessel was recommissioned as Schiff 111 after she was fitted out with the minelaying equipment from Schiff 4 on the Stülckenwerft.
On 9 Apr, 1940, the disguised minelayer took part in the invasion of Norway and went to Bergen. Off the harbour, the Norwegian patrol boat 201 tried to stop the vessel, but Schiff 111 continued her way. At 09.55 hours, she entered the harbour of Bergen and immediately dropped four mine barrages in the harbour entrance.
On 11 April, the ship touched a rock, while dropping a double mine barrage in the Soerfjord during a snow squall. The leaking ship was beached with a damaged screw in the Kirkefjord. The next day the ship was towed to Bergen. The ship was taken out of service and the crew was transferred with the minelaying equipment to the Norwegian minelayer Uller and the outpost vessel V-221. On 27 April, the vessel was given to the harbour defence flotilla Bergen as minelayer, but the fate of the ship is unclear. It is possible that she was lost one month later after hitting a mine.

At 14.30 hours on 24 Sep, 1939, the Hanonia was stopped by U-34 off Norway and brought to Kiel-Friedrichsort and later to Hamburg on 28 September by a prize crew, because the cargo of the ship had been bound for an English port.