She sailed 4 October from Norfolk, Virginia, with a convoy for the Mediterranean; and, after transporting precious supplies safely to Casablanca, returned to New York 16 November.

J. R. Y. Blakely made another round trip voyage to Casablanca December 1943 through January 1944, and a third during February through March 1944, as American ships began the great buildup in Europe.

During December the ship conducted additional training in the Caribbean, after which she sailed 16 January 1945 to participate in tactics out of Mayport, Florida.

The ships departed 27 March, and in the cruise which followed sank one of the U-boats, combining with other hunter-killer groups to foil the German plans.

Following carrier training operations, the ship sailed for the Panama Canal, arriving 19 July 1945, and joined the Pacific Fleet.

She reached San Diego, California, 29 July for onward routing to Pearl Harbor, where the ship celebrated the end of organized hostilities 15 August 1945.

Blakely steamed via the Panama Canal to New York 15 February, and after pre-inactivation overhaul arrived Green Cove Springs, Florida, 13 March 1946.