The USS S-6 was a United States Navy submarine, part of the S-class, launched on March 1, 1919. It was designed for coastal defense and had a displacement of about 1,000 tons when submerged. The submarine was equipped with four torpedo tubes and could carry a crew of around 40 men. During its service, the USS S-6 conducted various training exercises and operations. It was decommissioned in 1922 and later sold for scrap in 1931. The S-class submarines, including the S-6, played a significant role in the development of submarine technology during the early 20th century.