 After being commissioned at the Portsmouth Navy Yard on 31 March 1945, "Diablo" arrived at Pearl Harbor from New London, Connecticut on 21 July and sailed on her first war patrol on 10 August with instructions to stop at Saipan for final orders.With the ceasefire, her destination was changed to Guam where she arrived on 22 August 1945.On the last day of the month, she got underway for Pearl Harbor and the East Coast arriving at New York City on 11 October, except for a visit to Charleston, South Carolina in October where she remained at New York until 8 January 1946.