At 12.50 hours on 19 Jan 1942, the Kosmos II (Master Einar Gleditsch) spotted U-123 (Hardegen) from a distance of about 400 metres about 17 miles northeast off Cape Hatteras. The U-boat had troubles with one of the engines and steered a course out to the sea on the surface. The unarmed whale factory ship steered at full speed (about 17 knots) towards the U-boat and tried to ram it, while they send radio messages to notifiy the maritime authorities. The U-boat was out of torpedoes and the draught of the whale factory did not allow the U-boat to submerge. As the U-boat was only 75 metres from the ship, they managed to start the second engine and evaded the ship at full speed. The big ship followed the U-boat for over one hour, but it was making 18 knots and slowly got some distance to her. Hardegen thought about firing the machine guns at the ship to irritate the crew, but decided to fire two flares with the signal pistol at the bridge of the vessel.

At 05.37 hours on 28 Oct 1942 the Kosmos II (Master William Kihl) in convoy HX-212 was hit by one of two torpedoes fired by U-606 (Döhler) about 600 miles southeast of Cape Farewell, caught fire and fell behind convoy. The first mate was seriously injured during the explosion and the situation became very difficult, because 50 Greek passengers panicked and lowered lifeboats without orders. The master later ordered the most men on board to abandon ship in the lifeboats and stay alongside. About 50 men stayed, extinguished the flames and tried to catch up with convoy after the men in the lifeboats were picked up by the Barrwhin and some corvettes.

At 03.05 hours on 29 October, the Kosmos II was torpedoed by U-624, caught again fire and immediately settled. A third torpedo broke the ship in two, causing her to sink in 54°30N/29°55W. The most men were picked up by the Barrwhin after two and a half hours in a dramatic rescue operation. At 21.18 hours on 29 October, the Barrwhin was torpedoed and sunk by U-436 (Seibicke). Twelve men from Kosmos II died in the sinking, the survivors were picked up by the HMCS Kenogami (K 125) (Lt P.J.B. Cook) and landed at Londonderry.

The Kosmos II had carried at least 70 passengers and 30 soldiers. A total of 33 lives were lost: The master, 18 Norwegian crew members, six Norwegian soldiers, one Norwegian and two Greek passengers and five Norwegian (newly educated) mates who had belonged to a group of 20 who were going to Dumbarton for further education and training.

The three British landing craft HMS LCT-2190, HMS LCT-2192 and HMS LCT-2284 (each 291 tons) on deck were lost with the vessel.