[2] In 1886 France had built Gymnote, the first electrically powered submarine, solving the problem of a reliable underwater propulsion system.

This was followed with Sirene, an enlarged version of Gymnote (and renamed Gustave Zédé in 1891 honour of her designer), and Morse, with an experimental bronze alloy hull.

The electric propulsion, safe and efficient underwater, gave limited range and speed on the surface, restricting the submarine to operations near the coast.

This approach had been used before; Garrat's Resurgam in 1878 had used a steam engine on the surface, which had been used to pressurize steam to drive it underwater, and his partner Nordenfelt had continued with this approach; while Laubeuf's contemporary, JP Holland in the United States, had used a petrol engine for surface propulsion combined with electric when submerged for his submarine series.

Her hull shape also gave her a comfortable reserve of buoyancy, some 42%, which compared well to that of Holland's single-hulled electric boats, which remained at 2-3%.

[1] Narval was placed on order by the French Navy on 6 January 1898 and laid down at the Arsenal de Cherbourg on 23 November the same year.