シアトル・タコマ造船所
The name "St. Joseph" (making her the first United States Navy ship named for St. Joseph Bay, Florida) was assigned to MC hull 261, a converted C3-S-A1 cargo ship, on 23 August 1942. She was laid down on 25 March 1943 by the Seattle-Tacoma Shipbuilding Corporation of Tacoma, Washington. She was redesignated CVE-50 on 15 July, launched on 21 August 1943 and sponsored by Mrs. W.W. Smyth. The carrier was transferred to the UK on 22 December 1943 and commissioned the same day as HMS "Ruler" with the pennant number D72.