'Schneehuhn' was one of several German special operations effected via U-boats to reconnoitre and destroy Allied installations such as radio stations, coal mines and military outposts on Spitsbergen island (4/25 August 1944).

'Schneehuhn' was undertaken by Oberleutnant Friedrich-Georg Herrle’s 'Type VIIC' boat U-307, which reached Narvik in German-occupied northern Norway on 12 July 1944 after its seventh patrol in the Norwegian Sea. The boat then entered the Bogenbucht-Dock from 15 July to 17 July 1944, and on 18 July finished repairs at Narvik. On 29 July, the boat was provisioned at Ramsund and three new G-7e (T V) acoustic-homing torpedoes in place of the more standard G-7e (FAT II) weapons. On 1 August the boat took on 10 Waffen-SS special forces soldiers of SS-Oberführer Edmund Deisenhofer’s 5^th SS Panzerdivision 'Wiking' from U-703, which had arrived from Trondheim: some of these men were Norwegian SS volunteers.

U-307 departed the Bogenbucht at 10.00 on 2 August for Hammerfest via Tromsö. The boat reached Hammerfest at 21.15 on 3 August to embark the commander of the special forces team, SS-Untersturmführer Werner Koehl.

'Schneehuhn' began at 14.00 on 4 August as U-307 left Hammerfest for Spitsbergen. At 19.20 on 6 August, the boat arrived in the Isfjord of Spitsbergen and entered its inner part, the Sassenfjord, to disembark the 11 Waffen-SS commandos and three men of the boat’s own crew. At the Germans landed, they surprised a party of Norwegian soldiers led by Sergeant Schölberg Nilsen, which had arrived by motor boat, at Hilmar Nöis’s hut. The Norwegians retreated to the hills. After this the boat anchored in the nearby Gipsvika in 46 ft (14 m) of water, and on the following day moved farther to the west and sighted three Allied destroyers and three US submarine chasers off Barentsburg. These vessels were still too distant for immediate attack as the boat’s batteries possessed only a 50% charge. The boat had to stay submerged to prevent visual discovery, and moved back to the Sassenfjord.

On 7 August the German commandos had climbed the ridge between Adventtoppen and Hiorthfjell after departing from the Hanaskogdal. There the Germans discovered a well-developed but unmanned remote outpost of the Norwegian garrison centred on Longyearbyen, and found provisions, medicines, sleeping bags and mortar ammunition. Since the ammunition was too heavy for them to carry, the Germans hid it under some flat stones. Afterwards the Waffen-SS soldiers moved to the Hiorthfjellgruva coal mine, which had beeen shut down and lay at an altitude of 1,970 ft (600 m), and from an empty barrack observed Spitsbergen’s main settlements, Longyearbyen and Moskushamn. They estimated the Allied strength as 400 men with four anti-aircraft positions and ammunition stores; the airfield was found to be unusable. In Barentsburg the Germans observed only one manned artillery position.

On 8 August, U-307 reconnoitred the Sassenfjord, Isfjord and Bellsund farther to the south.

After further reconnaissance in the Longyearbyen area, the 11 commandos pulled back to the Diabasodden on the southern shore of the Sassenfjord, where they were embarked again by U-307 on 11 August. The boat then left the Isfjord, arrived off Cape Bjoerset on 12 August and again landed the commandos. On 14 August U-307 reconnoitred the Van Mijenfjord. On the following day the commandos fired the local refuge huts, together with provisions and equipment, on the eastern side of the Kaldbukta and at Langeneset on the Van-Mijenfjord. On 16 August two auxiliary military outposts in the nearby Muydenbukta were destroyed by the fire of the boat’s 88-mm (3.465-in) deck gun, and on the following day, in co-operation with the commandos, destroyed well-constructed coal mine power station and a radio station, as well as a small unoccupied settlement and a military outpost. In Sveagruva, at the eastern end of the Van Mijenfjord, 40 different buildings and facilities were blown-up, and the pier was set on fire.

After midnight on 18 August, U-307's look-outs spotted a large armed motor boat in the Van Mijenfjord. This was the motor boat Lennox of about 50-ton displacement and armed with one 0.5-in (12.7-mm) heavy machine gun. Lennox had put out to sea after the Allies had learned of a U-boat shelling settlements on Spitsbergen. U-307 begun to fire on the motor boat with its 37-mm and 20-mm automatic weapons at 00.28. The crew of Lennox replied with the machine gun, but the boat was swiftly overwhelmed, caught fire, blew up and sank at 00.40 near Cape Morton. The crew survived, the three men then coming ashore on a nearby stretch of coast and then managing to reach the Norwegian garrison.

(The Norwegian forces on Spitsbergen had eight three-man motor boats, each carrying a single heavy machine gun: two were in service during June 1942, two more arrived with the 'Gearbox II' undertaking on 17 September 1942, and four more arrived on 19 October 1943. Of these boats, one was sunk by the fire of U-302 at Signehamn in the Lillehöökfjord at 01.15 on 24 June in 'Nussbaum', and two more were destroyed at Longyearbyen on 8 September 1943 by the fire of German destroyers during the 'Sizilien' [or 'Zitronella'] raid on Spitsbergen.)

On 18 August the 11 commandos re-embarked at Russekeila Bay near Barentsburg, and U-307 set course once more for the central part of the Isfjord, where the Waffen-SS soldiers were put ashore near the Adventfjord.

Between 04.30 and 04.39 on 19 August, U-307 destroyed the Norwegian-manned anti-aircraft position at Cape Revneset, at the mouth of the Adventfjord, after the commandos had driven off the Norwegian defenders, who retreated to Longyearbyen. The Norwegian losses are not known, but two anti-aircraft guns and a 40-mm Bofors gun were destroyed by the U-boat’s deck gun, and the commandos blew up ammunition stocks and provision stores, and also burned nearby living barracks.

U-307 embarked all 11 commandos later on 19 August and departed the Isfjord. The German boat reconnoitred the western coast of Spitsbergen on 20 and 21 August. The boat operated as far to the north as Ny Aalesund, which was found to have been abandoned, and after this returned to Norway. U-307 entered Hammerfest at 06.30 on 23 August, continued to Tromsö on the next day, and entered Narvik at 11.00 on 25 August, so ending 'Schneehuhn'. In total, U-307 had covered some 1,900 miles (3060 km) on the surface and 120 miles (195 km) submerged.