United States E-class submarine

The United States E class submarines were used as coastal and harbor defense submarines prior to World War I. When hostilities broke out, the E class were used as training boats.

The submarines of this class were the first diesel-powered submarine. They were known as "pig boats", or "boats", due to foul living quarters and unusual hull shape.

The E class was also used to test and evaluate tactics and new equipment.

The E class was quickly overtaken by newer long range, ocean going submarines. The class was decommissioned in 1922 to comply with the Washington naval treaty.

Ships

 * USS E-1 (SS-24)
 * USS E-2 (SS-25)