TCG Gür was a German-designed submarine built in 1929-30 by the Echevarrieta y Larrinaga Shipyard in Cádiz, Spain, and bought by the Turkish Navy in 1935 where it served until 1947.

During its development and tests in Spain, it was designated Submarino E-1,[1] but actually it was a prototype (lead ship) of the German Type IA submarine.

Several German naval officers (including Wilhelm Canaris) visited Spain and struck a deal with a Spanish businessman, Horacio Echevarrieta.

A single submarine was built in 1929–1930, it was launched on October 22, 1930, and was tested at sea early in 1931, under the manufacturer's designation of E-1, since no navy had yet commissioned the ship.

The government of the Second Spanish Republic showed a clear preference for American submarine designs.