Initially named Omega, Argonaute was laid down in January 1903, launched in November 1905 and commissioned in 1911.

She was essentially an experimental submarine, and although in service during World War I, saw no action.

[1][2][3] Initially, Omega was to be equipped with a special diesel engine[note 1] to power the submarine both on the surface and submerged, but the failure of the concept on the French submarine Z forced the constructors to install a steam engine and an electric motor instead.

[1][4] She had a single shaft powered by one triple expansion steam engine of 350 horsepower (261 kilowatts) with steam from one boiler[note 2] and an electric motor which produced 234 hp (174 kW) for submerged propulsion.

[2][4] Argonaute served in the Mediterranean Sea until 20 May 1919, when it was struck from the Navy list.