The Soviet Union and Germany employed smaller coastal convoys to maintain the flow of supplies to the Soviet arctic coast, transport strategic metal ores to Germany, and sustain troops on both sides of the northern flank of the eastern front. Soviet convoys hugged the coast to avoid ice while German convoys used fjords to evade Royal Navy patrols. Both sides devoted continuing efforts to minelaying and minesweeping of these shallow, confined routes vulnerable to mine warfare and submarine ambushes. German convoys were typically screened by minesweepers and submarine chasers while Soviet convoys were often protected by minesweeping trawlers and torpedo cutters. A branch of the Pacific Route began carrying Lend-Lease goods through the Bering Strait to the Soviet Arctic coast in June 1942. The number of westbound cargo ship voyages along this route was 23 in 1942, 32 in 1943, 34 in 1944 and 31 after Germany surrendered in 1945. Total westbound tonnage through the Bering Strait was 452,393 in comparison to 3,964,231 tons of North American wartime goods sent across the Atlantic to Soviet Arctic ports. A large portion of the Arctic route tonnage was fuel for Siberian airfields on the Alaska-Siberia air route.
8 June 1940: With some of the longest range naval gunnery hits ever documented, Scharnhorst and Gneisenau sank the British aircraft carrier HMS Glorious and her escorting destroyers HMS Acasta and Ardent during Operation Juno.
9 July 1940: Raider Komet sailed north from Bergen and waited near Novaya Zemlya until 13 August 1940 for ice conditions to allow passage through the Matochkin Strait into the Kara Sea. Komet proceeded east with the assistance of three Soviet icebreakers to enter the Pacific Ocean through the Bering Strait on 5 September 1940. Soviet submarine Shch-423 made a similar trip from Murmansk to Vladivostok from 5 August to 17 October.
23 July 1941: Kriegsmarine destroyers Richard Beitzen, Hermann Schoemann, Friedrich Eckoldt and Karl Galster sank the Soviet survey ship Meridian near Teriberka.
30 July 1941: HMS Furious and Victorious launched airstrikes on Petsamo and Kirkenes. Victorious launched an airstrike on Tromsø on 31 July. These airstrikes turned back a patrol of Kriegsmarine destroyers.
26 August 1941: U-571 sank 3870-ton Mariya Ulyanova.
31 August 1941: The Dervish Convoy arrived in Arkhangelsk initiating transport of Allied war materials around Norway to the Soviet Union. The convoy was escorted by HMS Devonshire, Suffolk and Victorious, which launched airstrikes against Tromsø.
12 September 1941: Soviet submarine Shch-422 sank 1459-ton Ottar Jarl off Tanafjord 
3 December 1941: Soviet submarine K-3 was forced to surface after damages caused by German sub.chasers UJ 1403, UJ 1416 and UJ 1708. Submarine engaged the Germans in gunfire battle and UJ 1708 was sunk, while the others retreated.
11 January 1942: Convoy PQ 7 arrived in Murmansk after U-134 sank 5135-ton Waziristan.
Tirpitz waiting in Norway for another Allied convoy.
14 January 1942: Soviet submarine S-102 sank 1877-ton Turkheim off Sytlefjord.
17 January 1942: U-454 damaged 5395-ton Harmatris and sank HMS Matabele from convoy PQ 8 as the convoy reached Kola Bay. The German battleship Tirpitz was based at Trondheim, where its presence required the Home Fleet to retain at least one modern battleship which might have otherwise been used in the Mediterranean or Pacific.
5 February 1942: Soviet submarine Shch-421 sank 2975-ton Konsul Schulte off Porsangerfjorden.
10 February 1942: Combined convoys PQ 9 and 10 arrived in Murmansk escorted by HMS Nigeria, Faulknor and Intrepid. The escort departed with return convoy QP 7 on 12 February.
15 February 1942: Soviet submarine S-101 sank 1147-ton Mimona off Tanafjord.
5 March 1942: A Focke-Wulf Fw 200 located Convoy PQ 12 south of Jan Mayen. Tirpitz sailed on 6 March with destroyers Hermann Schoemann, Friedrich Ihn and Z25. The convoy covering force of HMS Duke of York, Renown, Kenya, Faulknor, Eskimo, Punjabi, Fury, Echo and Eclipse failed to locate Tirpitz; and Ihn sank the 2815-ton Ijora straggling from convoy QP 8. An unsuccessful airstrike from HMS Victorious on 9 March caused Tirpitz to seek refuge in Narvik.
27 March 1942: A Bv 138 located storm-scattered Convoy PQ 13 escorted by HMS Trinidad, Eclipse and Fury. KG 30 Junkers Ju 88s sank 4815-ton Raceland and 7007-ton Empire Ranger as Kriegsmarine destroyers Z24, Z25 and Z26 sailed. Z26 sank 4687-ton Bateau before being sunk by Trinidad. Trinidad and Eclipse were damaged in the engagement. U-376 sank 5086-ton Induna, and U-435 sank 6421-ton Effingham.
1 April 1942: Soviet submarine Shch-404 sank 2318-ton Michael off Tanafjord.
28 April 1942: Convoy QP 11 departed Murmansk escorted by HMS Edinburgh, Foresight, Forester, Bulldog, Amazon, Beagle and Beverley. U-456 torpedoed Edinburgh. Kriegsmarine destroyers Hermann Schoemann, Z24 and Z25 sank 2847-ton Tsiolkovski and damaged Amazon. Schoemann was sunk by Edinburgh while the German destroyers crippled Edinburgh and damaged Forester and Foresight.
29 April 1942: Soviet submarine M-171 sank 4969-ton Curityba off Varangerfjord.
HMS King George V with bow damage from collision with HMS Punjabi.
10 May 1942: Scheer moved from Trondheim to Narvik.
14 May 1942: A KG 30 Ju 88 dive bomber sank HMS Trinidad.
15 May 1942: The 11th U-boat Flotilla was established and based at Bergen for Arctic Ocean patrols. Sturzkampfgeschwader 5 (StG 5) Ju 87s attacked Murmansk, damaging 6187-ton Yaka and Soviet submarine Shch-403.
KG 26 He 111 torpedo planes attacked convoys PQ 15, 16 and 17.
4 July 1942: A He 115 sank Liberty shipChristopher Newport from convoy PQ 17; and KG 26 He 111s sank 4841-ton Navarino and damaged Liberty ship William Hooper and 6114-ton Azerbaidzhan. Twenty-two more ships were sunk by aircraft and U-boats after the convoy scattered on 5 July to avoid attacks by German surface ships.
U-255, painted white for arctic camouflage, returning to base after attacking convoy PQ 17.
12 September 1942: Convoy PQ 18 escort HMS Faulknor sank U-88 near Bear Island. U-405 and U-589 sank Liberty ship Oliver Ellsworth and 3559-ton Stalingrad on 13 September; while KG 26 and KG 30 bombers sank 5432-ton Wacosta, 4826-ton Oregonian, 6131-ton Macbeth, 5441-ton Africander, 6209-ton Empire Stevenson, 7044-ton Empire Beaumont and 3124-ton Sukhona. U-457 sank 8992-ton Atheltemplar on 14 September; and HMS Onslow sank U-589. HMS Impulsive sank U-457 on 16 September. The 5446-ton Kentucky was sunk and 6458-ton Troubador damaged before the convoy reached Murmansk.
13 September 1942: Convoy QP 14 sailed from Arkhangelsk. On 20 September U-435 sank HMS Leda, U-255 sank 4937-ton Silver Sword, and U-703 sank HMS Somali. U-435 sank 5345-ton Bellingham, 7174-ton Ocean Voice and 3313-ton Grey Ranger on 22 September.
29 October 1942: Operation FB attempted independent routing of Allied merchant ships. U-586 sank 6640-ton Empire Gilbert on 2 November. KG 30 Ju 88s sank 7363-ton Dekabrist and damaged Liberty ship William Clark and 5445-ton Chulmleigh which were sunk by U-354 and U-625. U-625 also sank 7455-ton Empire Sky; and Z27 sank 7925-ton Donbass on 7 November.
17 November 1942: Convoy QP 15 departed Kola Bay. A storm dispersed the convoy and sank escorting Soviet destroyer Sokrushitelny on 22 November.U-625 sank 5851-ton Goolistan, and U-601 sank 3974-ton Kuznets Lesov.
1 January 1943: Soviet submarine L-20 sank 5472-ton Muansa off Kongsfjorden. U-354 sank 2418-ton Krasnyj Partizan.
29 January 1943: Soviet submarines L-20 sank 7007-ton Othmarschen off Cape Nordkinn and M-171 sank 3243-ton Ilona Siemers off Kongsfjorden. U-255 sank the Soviet icebreaker Malygin and 1892-ton Ufa. U-255 then sank 7460-ton Greylock from convoy RA 52 on 3 February.
12 February 1943: Soviet submarine K-3 sank 8116-ton Fechenheim.
26 February 1943: Convoy JW 53 arrived in Kola Bay with one ship damaged by KG 30 Ju 88s. StG 5 Ju 87s damaged three more ships from the convoy on 27 and 28 February; air attacks on 6 and 13 March damaged another ship and sank 7173-ton Ocean Freedom.
5 March 1943: U-255 sank Liberty ship Richard Bland and 4978-ton Executive from convoy RA 53. U-586 sank 6076-ton Puerto Rican on 9 March.
12 March 1943: Tipitz, Scharnhorst and Lützow assembled in Narvik causing cancellation of Allied convoys through the summer.
16 March 1943: Soviet submarine M-122 sank 4533-ton Johannisberger off Varangerfjord.
29 March 1943: Soviet submarine S-55 sank 2297-ton Ajax. Also S-101 is said to have sunk her.
17 July 1943: Soviet submarine S-56 sank minesweeper M-346.
July - September 1943: German U-boats operated in Kara Sea against Soviet shipping: U-255 operated near Novaya Zemlya as a refueling station for a BV 138. The BV 138 searched for Kara Sea convoys to be attacked by Lützow and the Wiking Gruppe of U-302, U-354 and U-711. The U-boats torpedoed 3771-ton Petrovski and sank 2900-ton Dikson, 7169-tons Tbilisi, 2480-tons Arkhangel´sk and 4169-tons Sergej Kirov in addition to 3 minesweepers and 3 other auxiliary vessels. However U-639 was lost after being intercepted and torpedoed by Soviet submarine S-101 .
26 January 1944: Isegrim gruppe U-boats damaged HMS Obdurate and sank Liberty ships Penelope Barker, Andrew G. Curtin and Fort Bellingham from convoy JW 56A near Bear Island. On 30 January U-278 sank HMS Hardy with a G7es torpedo; and the convoy escort sank U-314.
28 January 1944: Soviet submarine S-56 sank 5056-ton Henrietta Schulte.
30 April 1944: U-711 sank Liberty ship William S. Thayer from convoy RA 59. Convoy escorts sank U-277, U-959 and U-674. The convoy covering force launched an airstrike sinking three ships from a German convoy near Bodø.
26 May 1944: Soviet aircraft sank 3402-ton Solviken and damaged 3672-ton Herta Engeline Fritzen near Kirkenes.
August–September 1944: German U-boats operations in Kara Sea against Soviet shipping resulted in the loss of three former American minesweepers of the Admirable-class transferred to the Soviets under Lend-Lease: T-118, T-114 and T-120 in addition to the Soviet corvette Brilliant . However only one merchant was lost: 7540-tons Marina Raskova (7540 GRT), in addition to a survey vessel. Germans lost U-362 after depth charges by Soviet minesweeper T-116 (another Admirable-class vessel transferred from United States).
2 December 1944: U-363 sank 1123-ton Proletari off Finland.
9 December 1944: Convoy RA 62 escorts sank U-387 at the mouth of Kola Bay. U-365 torpedoed HMS Cassandra on 11 December before being sunk by No. 813 Naval Air Squadron Swordfish from HMS Campania on 13 December.
30 December 1944: U-956 torpedoed 7176-ton Tbilisi off Kola Bay.
December 1944: The 14th U-boat Flotilla was established at Narvik to absorb displaced U-boats as bases on the French coast were captured by Allied troops.
14 February 1945: U-boats sank 8129-ton Norfjell and Liberty ship Horace Gray from convoy BK 3 outside Kola Bay.
17 February 1945: Escorts clearing Kola Bay for the departure of convoy RA 64 sank U-425.U-711 sank HMS Bluebell and U-968 damaged Liberty ship Thomas Scott and HMS Lark with G7se torpedoes. On 23 February KG 26 sank Liberty ship Henry Bacon – the last ship to be sunk by German aircraft in the second world war.
20 March 1945: U-968 torpedoed Liberty ships Horace Bushnell and Thomas Donaldson from convoy JW 65 and convoy escort HMS Lapwing with a G7se torpedo.
22 April 1945: U-997 sank 1603-ton Onega and torpedoed 4287-ton Idefjord from convoy PK 9.
29 April 1945: In the last trade convoy battle of the Second World War, U-286 sank HMS Goodall at the mouth of Kola Bay as convoy JW 66 escorts sank U-307 and U-286.
^Drent, Jan Commercial Shipping on the Northern Sea Route p. 4
^Wartime navigation over the ocean within the Arctic Circle should not be confused with the Arctic Ocean as it may have subsequently been defined to exclude areas within the Arctic Circle.