Propelled on the surface by two diesel engines producing a combined 6,000 horsepower (4,474 kW), they had a maximum speed of 18.6 knots (34.4 km/h; 21.4 mph).

Also called "deep-cruising submarines", their range on the surface was 10,000 nautical miles (19,000 km; 12,000 mi) at 10 knots (19 km/h; 12 mph).

Laid down at Chantiers Dubigeon in Nantes, France, on 25 August 1927[2] with the hull number Q151, Argo was launched on 11 April 1929.

[2] At the start of World War II in September 1939, Argo was assigned to the 4th Submarine Division based in Brest, France.

[3] She ran aground in fog while entering port at Casablanca on 5 July 1942 and suffered hull damage that kept her out of service for several weeks while undergoing repairs.

[3] In September 1943 Argo was detached to the United States Navy′s sound schools, first at Bermuda, then at New London, Connecticut, and later at Key West, Florida.

[9] Argo collided with the U.S. Navy Tacoma-class frigate USS Huron (PF-19) off Key West on 28 April 1945, suffering damage to both of her periscopes.