French submarine Plongeur Plongeur ( French for " Diver " ) was a French submarine launched on 16 April 1863 . She was the first submarine in the world to be propelled by mechanical ( rather than human ) power . Captain Siméon Bourgeois , who made the plans , and naval constructor Charles Brun began working on the design in 1859 at Rochefort . Specifications . The submarine used a compressed - air engine , propelled by stored compressed air powering a reciprocating engine . The air was contained in 23 tanks holding air at 12 . 5 bar ( 1 . 25 MPa , 180 psi ) , taking up a huge amount of space ( 153 m³ / 5 , 403 ft³ ) , and requiring the submarine to be of unprecedented size . The engine had a power of 60 kW ( 80 hp ) , and could propel the submarine for 5 nmi ( 9 km ) , at a speed of 4 kn ( 7 . 2 km / h ) . Compressed air was also used to empty its ballast tanks , which had a volume of 53 m³ ( 1 , 872 ft³ ) . Ballast was 212 tonne ( 234 long tons ) , including a security ballast of 34 t ( 37 tons ) . The submarine was armed with a ram to break holes in the hull of enemy ships , and an electrically - fired spar torpedo , fixed at the end of a pole . The submarine was 43 m ( 140 ft ) long and 381 t ( 420 tons ) in displacement . A support ship , the " Cachalot " , followed her in order to resupply the compressed air necessary to her propulsion . A small lifeboat ( 8 × 1 . 7 m ; 26 × 5 . 6 ft ) was provided for the escape of the 12 - man complement . Operational history . The submarine was commanded by Lieutenant de Vaisseau Marie - Joseph - Camille Doré , a native of La Rochelle . On 6 October 1863 , " Plongeur " made her first trials by sailing down the Charente river , towards the harbour of the Cabane Carrée . On 2 November 1863 , " Plongeur " was towed towards Port de Barques where her first underwater trials were planned . Because of poor weather conditions , the submarine was eventually towed to La Pallice and then to the harbour of La Rochelle ( Bassin à flot ) . On 14 February 1864 , during trials in the Bassin à flot , the engine raced due to an excessive admission of compressed air , and the submarine bumped into the quay . Trials were stopped . On 18 February 1864 , " Plongeur " was towed to La Pallice and dived to 9 m ( 30 ft ) . Stability problems due to its length limited the submarine to dives to a maximum depth of 10 m ( 33 ft ) . The front of the submarine would tend to dive first , hitting the bottom , so that the submarine would glide forward . Pumps were installed to compensate for the tilt , but proved too slow to be effective . The installation of longitudinal rudders would have improved stability as later demonstrated by the " Gymnote " and " Gustave - Zédé " submarines . A model of " Plongeur " was displayed at the 1867 Exposition Universelle , where it was studied by Jules Verne , who used it as an inspiration and 3 years later published his novel " Twenty Thousand Leagues Under the Sea " . After various experiments , the French Navy struck the ship on 2 February 1872 . Conversion . The submarine was reactivated as an automotive water tanker , equipped with a compound 2 - cylinder steam engine of 90 kW ( 120 hp ) , on 1 January 1873 . She was assigned to the harbour of Rochefort . She was equipped with a new engine in 1898 , transferred from a torpedo boat ( Torpilleur No 74 ) . In 1927 , upon the closure of the arsenal at Rochefort , she was transferred to the Mediterranean at Toulon , where she was used to supply the 1st and 3rd squadrons with water . She was decommissioned on 25 December 1935 , and sold for 25 , 143 " francs " to a M . Negai on 26 May 1937 .