The F-class submarines were a group of four submarines designed for the United States Navy by Electric Boat in 1909. F-1 and F-2 were built by Union Iron Works in San Francisco, while F-3 and F-4 were built by The Moran Company in Seattle, Washington.

The E-class submarines were a class of two United States Navy submarines, built by the Fore River Shipbuilding Company of Quincy, Massachusetts, under a subcontract from the Electric Boat Company. They were used as coastal and harbor defense submarines prior to World War I. When hostilities broke out, the E class were mostly used as training boats; however, E-1 operated on war patrols based in the Azores. During this time, the need for an improved permanent bridge structure was discovered; the temporary piping-and-canvas bridges were inadequate in the North Atlantic.