[1] After acceptance trials in Cape Cod Bay, R-2 was assigned to Submarine Division 9 of the United States Atlantic Fleet and based at New London, Connecticut.

R-2 was transferred to the United States Pacific Fleet on 14 April 1921, transited the Panama Canal on 28 May 1921, and arrived on 30 June 1921at her new base, San Pedro, California.

Leaving Pearl Harbor, Hawaii, on 12 December 1930, R-2 was reassigned to the Atlantic Fleet and arrived at New London via the Panama Canal on 9 February 1931.

Based there for the remainder of her career, she was attached to the Fleet Sonar School, and assigned periodically to defensive patrols in keeping with her limited operational capabilities.

She was sold to Rosoff Brothers of New York City on 28 September 1945, resold to the Northern Metals Company of Philadelphia in October 1945, and scrapped in early 1946.