World War II North Atlantic operations

Between 27 February and 1 May 1944, Cates guarded two convoys carrying American troops to ports in Ireland and Wales in the lengthy preparations for the invasion of Normandy. Overcoming the threat of submarine attack and the ever-present hazards of vicious North Atlantic weather, she aided in the completely safe passage of critically needed men.

After a brief period training with submarines from New London, Connecticut, Cates completed 1944 with five convoy voyages from New York to ports in Ireland, Great Britain, and France escorting tankers, carrying critical petroleum products to support the push of the Allies across Europe. Cates opened 1945 with a brief training period in Casco Bay, Maine, then a return to tanker convoy duty from Boston, Massachusetts, to Scotland, returning to New York 18 February. Two weeks later she sailed in the escort of another convoy, but had to break off and return to Earle, New Jersey, for repairs, followed by refresher training in Casco Bay. This training became most realistic when Cates took part in a 2-week anti-submarine sweep along the northeast coast. She returned to New York 20 April, and sailed 4 days later escorting tankers to Liverpool.

Transfer to Pacific Theatre operations

Returning to New York with empty tankers 23 May 1945, Cates sailed on to training in Cuban waters, passed through the Panama Canal, and arrived at Pearl Harbor 31 July for training and overhaul. Arriving at Eniwetok 30 August, she began six months of convoy escort supporting the redeployment of troops in the Far East, calling at ports in the Philippines, Japan, and Okinawa until 18 February 1946.