Armed with 40 mm guns in lieu of torpedo tubes, Hubbard sailed with her first convoy on 1 June, seeing the transports safely to Bizerte, Tunisia and returning to New York on 19 July 1944.

The ships arrived New York on 6 February and, after additional training in Casco Bay, sailed again to search for submarines 4 April from NS Argentia, Newfoundland.

Hubbard returned to Boston on 10 May 1945 and began her conversion to a Charles Lawrence-class high speed transport, suitable for the still-active Pacific War.

She was reclassified APD-53 on 1 June 1945 and emerged from Sullivans Dry Dock, Brooklyn, on 14 August, the day before the surrender of Japan.

Following three months of training operations in the Caribbean and Casco Bay, Hubbard arrived Green Cove Springs, Florida, on 12 November 1945.