The USS S-38 was a United States Navy submarine, part of the S-class, launched on March 1, 1921. It was designed for coastal defense and had a displacement of about 1,000 tons when submerged. The submarine was equipped with torpedoes and had a crew of around 40 men, allowing it to operate effectively in shallow waters. During its service, the USS S-38 conducted various training exercises and patrols, primarily in the Pacific Theater. It was decommissioned in 1945 and later sold for scrap. The submarine is notable for its role in the development of submarine warfare tactics during its operational years.