On 10 May, Operation RY commenced. After the operation's flagship, minelayer , was sunk by the U.S. submarine on 12 May (), the landings were postponed until 17 May. In the meantime, Halsey's TF 16 reached the South Pacific near Efate and, on 13 May, headed north to contest the Japanese approach to Nauru and Ocean Island. On 14 May, Nimitz, having obtained intelligence concerning the Combined Fleet's upcoming operation against Midway, ordered Halsey to make sure that Japanese scout aircraft sighted his ships the next day, after which he was to return to Pearl Harbor immediately. At 10:15 on 15 May, a Kawanishi reconnaissance aircraft from Tulagi sighted TF 16 east of the Solomons. Halsey's feint worked. Fearing a carrier air attack on his exposed invasion forces, Inoue immediately canceled "RY" and ordered his ships back to Rabaul and Truk. On 19 May, TF 16 – which returned to the Efate area to refuel – turned towards Pearl Harbor and arrived there on 26 May. "Yorktown" reached Pearl the following day.