As U.S. forces began to close in on the islands of Attu and Kiska, the Japanese found it harder and harder to keep their troops on these islands supplied. Convinced that the loss of these islands would inevitably lead to American attacks on Japan's Kurile Islands.  ADM Hosogaya of the Imperial Japanese Navy decided that the safest way to keep the islands supplied would be through submarines. The Japanese on the islands did not feel that this could keep them sufficiently ready for battle, and on 6 March, 1943 Hosogaya was ordered to send a transport convoy to the island. It made it to islands without complications. Again ordered to send a convoy, Hosogaya himself set out from the Kuriles on 23 March with three large transport ships escorted by almost all of Japan's 5th Fleet. (Perras)
        This time, however, the Americans had intercepted word of the attempt and a naval blockade of the islands had been set up by RADM Kinkaid. Task Force-16.6 headed by RADM McMorris was assigned the job, although they only had two heavy cruisers and a few destroyers. Still, McMorris was confident. Intelligence had told him that the IJN could only muster a convoy of about the same strength. On 26 March, Hosogaya's convoy tried to run the blockade. The ensuing battle was the largest sea fight of the whole Aleutian campaign and the longest daylight surface naval battle. Named for the closest land mass, the Battle of the Komandorski Islands ending with the smaller American force sending Hosogaya away without completing his mission, thus limited the supplies that reached the island bound Japanese to those brought through by submarines. (United States Navy)