USS O-7 (SS-68) was one of 16 O-class submarines built for the United States Navy during World War I. Description The O-class submarines were designed to meet a Navy requirement for coastal defense boats. The submarines had a length of overall, a beam of and a mean draft of . They displaced on the surface and submerged. The O-class submarines had a crew of 29 officers and enlisted men. They had a diving depth of . For surface running, the boats were powered by two diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a electric motor. They could reach on the surface and underwater. On the surface, the O class had a range of at . The boats were armed with four 18 inch (450 mm) torpedo tubes in the bow. They carried four reloads, for a total of eight torpedoes. The O-class submarines were also armed with a single 3"/50 caliber deck gun. Construction and career O-7 was laid down on 14 February 1917 by the Fore River Shipbuilding Company in Quincy, Massachusetts. She was launched on 16 December 1917 sponsored by Mrs. Constance Sears, and commissioned on 4 July 1918 with Lieutenant Commander Frederick C. Sherman, in command. During the final stages of World War I, O-7 operated out of Philadelphia, Pennsylvania, on coastal patrol from Cape Cod to Key West, Florida. On 2 November she departed Newport, Rhode Island, with a 20-sub contingent bound for European waters, however, the Armistice with Germany was signed before the ships reached the Azores, and they returned to the United States. In 1919, O-7 reported to the newly established Submarine School at New London, Connecticut, to train there for the next decade. In 1924, she went to Coco Solo for maneuvers and was reclassified a second line submarine on 25 July 1924. Returning to New London, she reverted to first line on 6 June 1928. In January 1930, she joined her sister ships in a run to Portsmouth, New Hampshire, thence back to New London in February. After returning from Washington, DC. in July, she continued operations at New London. She sailed to Philadelphia, Pennsylvania, on 23 February 1931 and decommissioned there on 1 July 1931. After a decade in mothballs, O-7 was recalled to active duty and recommissioned at Philadelphia 12 February 1941. She reported to New London in May and trained sub crews