After shakedown in the Caribbean and training along the Atlantic coast, the new light cruiser, accompanied by her sister-ships and , departed Boston on 16 April 1944 for the Pacific, via the Panama Canal and San Diego, reaching Pearl Harbor on 6 May. "Miami" joined the Fast Carrier Task Force for air strikes in June against Saipan, Tinian, Rota, Guam, Pagan, and the Bonin Islands in support of the Marianas campaign.