Through the end of 1942, "McCormick" plied the North Atlantic on runs to Halifax, NS Argentia, and Londonderry Port. Shifting southward, 7 February 1943, she escorted convoys bound for Casablanca. On 12 July, on a return voyage, , providing air cover for the convoy, was relieved by . But before "Santee" departed the area, four U-boats were discovered in the convoy’s vicinity. For the next 4 days, planes from the carriers scouted and destroyed all four: "Santee", on the 14th and on the 15th; "Core", on the 13th and on the 16th. On the last date, "McCormick" picked up three survivors from "U-67" for later transferral.