Commissioned in 1924, S-27 spent the interwar years involved in the usual training exercises. At the time World War II began, she was at Mare Island, undergoing a refit.
Her initial wartime service was in San Diego, where she took part in training duties. She was sent to Dutch Harbor, in the Aleutian Islands, in May 1942.
On 19 June 1942, S-27 ran aground on a reef off St. Makarius Point. The crew made every effort to refloat her, but this proved to be impossible and she was abandoned, with the crew being ferried ashore in a rubber raft. The crew was later picked up by amphibian aircraft. S-27 was broken up on the reef by wave action.
Builder: Fore River
Sponsor: Mrs. Frank Baldwin
First Captain: Lt. Thoedore Waldschmidt
Stricken/Lost: Lost 6/19/42