USS S-1 was transferred to the Royal Navy at New London on 20 April 1942. In July 1942 she arrived in the UK. She went to the South Atlantic as an anti-submarine warfare training vessel. She arrived in South Africa, via Gibraltar and Freetown, in December 1942. She was not in good material condition, and spent much of her time in dockyard hands. She was declared unseaworthy following a collision in Durban harbour in January 1944, and paid off into reserve. She was returned to the United States Navy on 16 October 1944. Sold for scrap locally at Durban on 20 June 1946. Scrapped at Durban on 14 September 1946.