Propulsion while surfaced was provided by two Normand-Vickers diesel motors with a total of 1,300 bhp (969 kW) and while submerged by two electric motors providing a total of 1,000 hp (746 kW) through two shafts enabling a maximum speed of 12 knots (22 km/h; 14 mph) while surfaced and 9 knots (17 km/h; 10 mph) while submerged.

[3] The Saphir-class submarines were designed to launch torpedoes and lay mines without surfacing.

The moored contact mines they could lay contained 220 kilograms (485 lb) of TNT and could be laid in up to 200 metres (656 ft) of water.

They were attached to the submarine's exterior under a hydrodynamic protection[clarification needed] and were jettisoned with compressed air.

[8] Of the remaining submarines, Diamant was scuttled at Toulon on 27 November 1942;[9] Nautilus, Saphir and Turquoise were demobilized in Bizerte between 1941 and 1942.