USS L-4 (SS-43)

USS L-4 (SS-43) was an L-class submarine of the United States Navy. Her keel was laid down on 23 March 1914 by Fore River Shipbuilding Company in Quincy, Massachusetts. She was launched on 3 April 1915 sponsored by Mrs. Stephen A. Gardner, and commissioned on 4 May 1916 with Lieutenant (junior grade) Lewis Hancock, Jr., in command.

Service history
Assigned to the Atlantic Submarine Flotilla, L-4 operated along the Atlantic coast, assisting in the development of new techniques in undersea warfare until April 1917.

Following the declaration of war on the Central Powers, the United States Navy dispatched submarines to European waters to protect the Allied shipping lanes. After a Philadelphia, Pennsylvania, overhaul, L-4 departed Newport, Rhode Island, on 4 December and steamed for the Azores. She departed Ponta Delgada on 19 January 1918, arriving for patrol operations at Berehaven, Ireland, on 27 January. While on patrol during April, L-4 twice encountered enemy U-boats in British waters and chased them from the paths of friendly convoys.

Based at Berehaven for the rest of the war, U.S. submarines protected Allied shipping from U-boat attacks. Following the Armistice with Germany, L-4 departed the Isle of Portland, England, on 3 January 1919 for the United States, arriving Philadelphia on 1 February.

For the next two years, the submarine operated along the East Coast performing experiments developing the tactics of undersea warfare. L-4 decommissioned at Philadelphia on 14 April 1922 and was sold to Pottstown Steel Company in Douglassville, Pennsylvania, on 31 July 1922 for scrapping.