French submarine Surcouf performed well during trials according to the Dutch magazine Marineblad dated 1932 no. 5

An item reported that the trials of the French submarine Surcouf (1) with a displacement of 2.880 (surfaced)-4.304 (submerged) tons were very successful according to an article written by Gautreau in the magazine N.&M. Rec dated 15 June. He thought that in wartime she could be a nasty surprise for the enemy. With a good commanding officer was she able with her range of 10.000 nautical miles and her armament of 2-20,3cm guns and 16 torpedo tubes to perform very well. Further more was she seaworthy and possessed she suitable crew accommodation. She was according to the writer the French response to the British submarine HMS X 1 (2) for which this was the only reason she was built and probably without a sister ship.

Notes
1. Submarine cruiser. Her building was ordered in December 1927, launched on 18 October 129m commissioned in May 1934 and sunk on 18 February 1942 around 70 nautical miles north of Christóbal and actually stricken of the navy list on 6 December a year later. Although there were three planned to be built was she the only one realized. In fact a underwater cruisers. Displacement 2.930 (dead)-3.300 (surfaced)-4.373 (submerged) tons and as dimensions 110 x 9 x 7,25 (draft) metres or 361’x 26’6”x 23’9”.
2. The HMS X 1 was laid down at the Chatham navy dockyard on 2 November 1921, launched on 16 November 1923, commissioned in December tow years later and broken up at Pembroke in 1936. This submarine cruiser was when she was launched the largest submarine of her time with a displacement of 2.820 (surfaced)-3.700 (submerged) tons and as dimensions 110,79 x 9,07 x 4,6 metres or 393’6”x 29’9” x 15’. For example the Dutch submarine Hr. Ms. O 9 laid down at the shipyard of the Kon.Mij. De Schelde on 23 September 1921 and commissioned on 18 January 1926 had a displacement of 526 (surfaced0-656 (submerged) tons and as dimensions 54,66 (over all) x 5,70 x 3,53 metres. The Dutch submarine K XI laid down at the Dutch shipyard Fijenoord, Rotterdam on 9 December 1922 and commissioned on 24 March 1924 was slight larger as the O 9 with a displacement of 688 (surfaced)-828 (submerged) tons and as dimensions 66,70 (over all) x 6,15 x 3,78 metres.