The Battle of the Komandorski Islands was a naval battle between American and Imperial Japanese forces which took place on 27 March 1943 in the North Pacific, south of the Soviet Komandorski Islands. The Japanese were escorting a three ship convoy, while the Americans were patrolling waters west of the Aleutian Islands. The battle was a daylight surface engagement in which air support played no role and in which the outnumbered American force escaped greater damage after the Japanese chose to withdraw.
In June 1942, Japanese forces landed in the western Aleutian Islands of Kiska and Attu, as a northern pincer of the main attack on Midway Island. After the stunning Japanese defeat at Midway, the Japanese held the islands as a defensive shield against any American attempt against the Kuriles. As the U.S. was preparing its assault on the Japanese strongholds, Japanese shipping between Japan and the islands was harassed by submarines and aircraft. The Japanese Imperial Navy countered this threat by sailing at night or taking advantage of stormy weather. Aware of Japanese tactics, Admiral Thomas C. Kinkaid deployed a surface force around Attu. On the night of 19/20 February 1943, the patrol force, consisting of the heavy cruiser Indianapolis and the destroyers Coghlan and Gillespie, shelled and sank the Japanese transport ship Akagane Maru (3100 GRT) west of Attu.
In a bid to defy the American blockade, Vice-Admiral Boshirō Hosogaya, in charge of the 5th Fleet and the northern theatre of operations, assembled a high-speed convoy with the two fast merchant ships Asaka Maru (7399 GRT) and Sakito Maru (7158 GRT) and a slower transport, the Sanko Maru (5491 GRT). The latter and her escort, the destroyer Usugumo, were to make a rendezvous with the main force south of the Komandorski Islands. The ships carried materiel essential to complete the building of an all-weather airstrip at Attu.
When Admiral Kinkaid became aware of Japanese plans to send a supply convoy to their forces on the Aleutian Islands of Alaska, U.S. Navy ships commanded by Rear Admiral Charles McMorris were sent to prevent this. The fleet consisted of the heavy cruiser Salt Lake City, the light cruiser Richmond and the destroyers Coghlan, Bailey, Dale and Monaghan.
American intelligence estimated that the Japanese escort consisted of one heavy cruiser, one light cruiser, and four destroyers. However, the Japanese 5th Fleet had been reinforced by two more cruisers, so that the Japanese escort force actually consisted of the heavy cruisers Nachi and Maya, the light cruisers Tama and Abukuma, and the destroyers Wakaba, Hatsushimo, Ikazuchi, and Inazuma. Vice Admiral Boshirō Hosogaya hoisted his flag on Nachi. Rear-Admiral McMorris didn't learn that he was facing a superior force until one hour after the first radar contact.
On the early morning of 27 March 1943, the Japanese convoy was intercepted by the American picket line some 100 nautical miles south of the Komandorski islands and 180 nautical miles west of Attu, just to the west of the International Date Line. Despite lacking radar, the Japanese cruiser squadron spotted the American force half an hour earlier than the Americans spotted them, in part because the southern horizon was lightening earlier than the northern, and because the Japanese navy strictly selected lookouts of exceptional visual acuity. Because the battle was a chance encounter in a remote location on the open ocean, neither fleet had air or submarine assistance, so that it was one of the few engagements exclusively between surface ships in the Pacific Theater and one of the last pure gunnery duels between fleets of major surface combatants in naval history. At one point, McMorris sent a request for air support to the USAAF air base at Adak. However, the B-24 squadron sent to attack the Japanese force became lost in the fog and had to return home. A spotter aircraft from Nachi directed fire on the American force for the whole battle. While the Japanese side criticized the observers' inability to deal with smoke screens, the US reports say that the accurate way in which the enemy gunners shifted their fire led the Americans to believe that one of the Japanese cruisers had fire control radar.
Although the Japanese cruisers heavily outgunned the American force and inflicted more damage, the engagement was tactically inconclusive. The U.S. Navy warships escaped destruction after a Japanese misjudgment: with the Japanese fleet on the edge of victory, Admiral Hosogaya – not realizing the heavy damage his ships had inflicted and fearing American war planes would appear – chose to retreat, conceding a strategic victory to the US Navy. Indeed, the battle ended Japanese attempts to resupply the Aleutian garrisons by surface ship, leaving only submarines to conduct supply runs. The airstrip at Attu was never finished. Hosogaya was accordingly retired from active service after the battle and assigned to govern a group of South Pacific islands.
This is a timeline of the action based on accounts by O'Hara and Millsap.
0600: The United States ships were formed in a scouting line at six-mile intervals zig-zagging at 15 knots on base course 020°.
0700: While the Japanese formation was turning 180° to a northern course, the destroyer Inazuma, still heading south, spotted unknown ships 27000 yards to port. A navigating officer on one of the transports visually observed the American force minutes later.
0715: As the day dawned, the ships were identified as American.
0730: Hosogaya ordered a turn to starboard, to the southeast, while the two fast transports were ordered to withdraw north-northwest, escorted by Inazuma.
0730: The lead ships Coghlan and Richmond made radar contact with the two trailing Japanese transports and a destroyer on course 080° at 13 kn (15 mph; 24 km/h).
0740: The Americans changed course to 080° and the rear ships increased speed to operate as a compact group. Five radar blips were counted.
0755: The Japanese turned northward to course 340° and the Americans came to course 000° to follow.
0811: The Americans visually identified the radar contacts as two transports, two light cruisers, and a destroyer.
0820: The Americans sighted the masts of four more Japanese ships on the horizon.
0835: The Americans identified the masts as two heavy cruisers and two destroyers and turned to course 240°.