USS N-7 (SS-59), also known as "Submarine No. 59", was an N-class coastal submarine of the United States Navy commissioned during WWI. She spent the war patrolling off the coast of New England, and was decommissioned after less than four years in service.
The N-class boats designed by Electric Boat, N-1 throughN-3, also referred to as the N-1-class, were built to slightly different specifications from the other N-class submarines, which were designed by Lake Torpedo Boat, referred to as the N-4-class. The Lake submarines had a length of overall, a beam of , and a mean draft of . They displaced on the surface and submerged. The Lake submarines had a crew of 3 officers and 26 enlisted men. They had a diving depth of .
For surface running, the Lake submarines were powered by two Busch-Sulzer diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a Diehl electric motor. They could reach on the surface and underwater.
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.
N-7s keel was laid down on 20 April 1915, by the Lake Torpedo Boat Company, in Bridgeport, Connecticut. She was launched on 19 May 1917, sponsored by Mrs. Anne Miller, and commissioned on 15 June 1918.
After fitting out at New London Submarine Base, in Groton, Connecticut, she patrolled the New England coast, to guard against attacks by German U-boats, until 17 September, when she put into New York, for upkeep.
Returning to New London, on 24 October, she remained there until 21 June 1919, when she sailed to the Philadelphia Navy Yard, in Philadelphia, Pennsylvania, for extensive overhaul. She returned to New London, on 31 March 1920, and remained there until placed in reserve on 7 June.
N-7 spent 1921, in reserve, at New London, except for short cruises to Boston, Massachusetts, and Newport, Rhode Island. Later that year, her engines were transferred to a more modern L-class submarine.
On 26 January 1922, towed by the fleet tug , she departed for Philadelphia, where she decommissioned on 7 February. Her hulk was sold to Joseph G. Hitner, of Philadelphia, for scrap on 5 June 1922.