submarines in it. He had been designated the commander of the Special Attack Unit, made up of all five submarines, each of which was to launch a Type A midget submarine off Pearl Harbor so that the midget submarines could participate in the attack. I-22 was to serve as flagship of the Special Attack unit. On 18 November 1941, the five submarines moved from Kure to the Kamegakubi Naval Proving Ground, where each embarked a Type A midget submarine. At 02:15 on 19 November 1941, the five submarines got underway from Kamegakubi bound for the Hawaiian Islands, taking a direct route that took them south of Midway Atoll. While at sea, they received the message "Climb Mount Niitaka 1208" () from the Combined Fleet on 2 December 1941, indicating that war with the Allies would commence on 8 December 1941 Japan time, which was on 7 December 1941 on the other side of the International Date Line in Hawaii. World War II Pearl Harbor At 02:15 on 7 December 1941, I-18 launched her midget submarine, No. 17, south of Oahu about from the entrance to Pearl Harbor. No. 17 was depth charged and sunk with the loss of its two-man crew outside the harbor in Keehi Lagoon. Its wreck was discovered resting in of water on 13 June 1960, and the United States Navy submarine rescue ship refloated it on 6 July 1960, finding no human remains inside. At the request of the Government of Japan, the United States returned the wreck to Japan, where it is displayed at the Naval Academy Etajima in Etajima. I-18 and the other four "mother" submarines proceeded to the planned recovery area for their midget submarines west of Lanai, where they spent the night of 7–8 December 1941. None of the midget submarines returned. Early on 9 December 1941, I-18, I-20, and I-24 received orders to leave the recovery area. I-18 departed the Hawaiian Islands on 12 December 1941 and arrived at Kwajalein on 22 December 1941. First war patrol On 4 January 1942, I-18, I-22, and I-24 departed Kwajalein to begin their first war patrol, assigned patrol areas off the Hawaiian Islands, with the commander of Submarine Division 2 embarked on I-18. I-18 sighted U.S. Navy Task Force 11, including the aircraft carrier , steaming west of Hawaii on 9 January 1942, and on 10 January, while northeast of Johnston Island, she sighted