[1] For surface running, the Electric Boat submarines were powered by two 240-brake-horsepower (179 kW) diesel engines, each driving one propeller shaft.

After fitting out and conducting sea trials in Puget Sound, N-2 departed the Navy Yard 21 November 1917, and sailed for San Francisco, California, in company with her sister ships N-1 and N-3.

Upon arriving at San Francisco, California, she was ordered to proceed to the East Coast via the Panama Canal, for assignment to the Submarine Force, U.S. Atlantic Fleet.

She arrived at New London, Connecticut, on 7 February 1918 and almost immediately began to patrol along the New England coast, guarding against enemy submarines in this area for the remainder of the war.

Beginning in late May 1921, the submarine also tested experimental Navy weapons, such as a radio controlled torpedo, and evaluated its potential value in modern combat.