(SS71: dp. 520.6 (surf. n.), 629 (subm.); l 1724; b. 18 Ό; dr. 145; s. 14 k. (surf.), 10.5 k. (subm.); cpl. 29; a. 1 3, 4 18 tt.; cl. O1).
O10 was laid down 27 February 1917 by the Fore River Shipbuilding Co., Quincy, Mass.; launched 21 February 1918; Sponsored by Mrs. John E. Bailey; and commissioned 17 August 1918, Lt. Sherwood Picking in command.
O10 added to U.S. efforts in World War I operating out of Philadelphia on coastal patrol against U-boats until 2 November, when she departed Newport with other subs for service in European waters. The Armistice was signed before the ships reached the Azores, however, and the ships returned to the United States.
In 1919, O10 joined others of her class at New London to train sub crews at the submarine school there. In 1924, O10 steamed to Coco Solo, where she was re-classified as a 2nd line submarine 25 July 1924. Returning to operations at New London, she reverted to 1st line 6 June 1928. She continued at New London until January 1930, when she sailed north to Portsmouth, N.H. returning to New London in February. She continued training duties until February 1931, when she sailed to Philadelphia, decommissioning there 25 June.
With the approach of U.S. involvement in World War II, there was a recognized need for numerous training subs. O10 recommissioned at Philadelphia 10 March 1941 and went to New London in May. She departed on a trial run to Portsmouth, N.H., 19 June 1941, the day before O9 failed to return. O10 joined in the search for her sister ship but found no trace of her. At 1655 on 22 June, Triton, with Secretary of the Navy Knox on board, fired a 21-gun salute for the crew lost on the ill-fated sub.
Returning to New London, O10 trained crews there until wars end. She then sailed to Portsmouth, N.H. and decommissioned there 10 September 1945. Struck from the Navy Register 11 October 1945, she was sold to John J. Duane Co. of Quincy 21 August 1946.