(SS-73: dp. 491 (surf.), 566 (subm.); l 175-; b. 16-7-; dr. 13-11-; s. 14 k. (surf.), 11 k. (subm.); cpl. 29; a. 1 3-, 4 18- tt. cl. O-11)
O-12 (SS-73) was laid down 6 March 1916 by the Lake Torpedo Boat Co., Bridgeport, Conn.; launched 29 September 1917; sponsored by Mrs. Homer S. Cummings; and commissioned 18 October 1918, Lt. Comdr. J. E. Austin in command.
Submarine O-12 spent much of her career as a unit of submarine Division 1, based at Coco Solo, Panama Canal Zone. In 1921 she was awarded a Battle Efficiency Pennant and trophy for gunnery (gun and torpedo). She decommissioned 17 June 1924 and was placed in reserve at the Philadephia Navy Yard.
Struck from the Naval Register 29 July 1930, she transferred to the United States Shipping Board for conversion by the Philadelphia Navy Yard for use on the Sir Hubert Wilkins Arctic Expedition of geophysical investigation.
After use by Lake and Dannenhower, Inc. of Bridgeport, Conn. for the Wilkins-Ellsworth Artie Expedition, during which the submarine bore the name "Nautilus," O-12 was returned to the Navy Department. She was sunk 20 November 1931 in a Norwegian fjord.