As China quietly completes its secret nuclear submarine Type 095 (110 meters in length, 10,000 tons, with an X-shaped rudder unseen on Chinese submarines and pump-jet propulsion to reduce its acoustic signature) and the United States deploys the new-generation Virginia-class submarines, France responds with the stealthiest and most lethal submarine it has ever built.
The De Grasse, fourth example of the Suffren class delivered by Naval Group, inherits the stealth of nuclear-armed attack submarines and adds a cruise missile capable of hitting ground targets at more than 1,000 kilometers, without needing to raise its sail or reveal its position.
The Deadliest European Submarine
Naval Group officially handed over to the French Directorate General for Armaments (DGA) the De Grasse nuclear attack submarine, on June 25, 2026. It is the fourth of six submarines planned under the Barracuda program, operatively known by the Marine Nationale (the French Navy) as the Suffren class and intended to replace the veteran Rubis class, in service since the early 1980s.
The De Grasse measures 99 meters in length, 8.8 meters in diameter and displaces 4,700 tons on the surface and 5,200 when submerged, almost double that of a Rubis (2,600 tons). It carries a reduced crew, around 65 sailors, five fewer than on a Rubis despite its larger size, thanks to a high degree of automation.
One of the cornerstones of the Suffren class stealth is its pump-jet propulsion. This propulsion system replaces the conventional open propeller with a rotor enclosed within a fixed cylindrical housing, called the stator, which is integrated into the stern of the submarine. The rotor, driven by the turbine shaft, draws water in from the front of the housing and expels it under pressure at the rear, generating thrust. The stator, with its fixed blades, straightens the water flow before it exits, improving efficiency and reducing turbulence.
The advantage over an open propeller is mainly acoustic. It is the standard solution in the latest-generation nuclear submarines of the world’s leading navies precisely because acoustic stealth is the factor that weighs most in the design of a modern submarine.
To that design are added vibration dampers and hull insulation materials from the same generation of missile-launch submarines. The De Grasse also features a dry hangar at the rear of the sail capable of housing up to 12 special forces operators, who can enter and exit the submarine while submerged.
Another technical breakthrough of the Suffren class is the elimination of the traditional optical periscope, that tube that physically pierced the pressure hull and forced the commander to manually rotate it to observe the surface. Instead, the submarine incorporates optronic masts, such as high-definition, thermal, and low-light cameras mounted on top of the sail, which transmit the image digitally to the consoles at the operations center. The system removes the structural vulnerability point that the periscope well represented and frees interior space for the crew.
In armament, the Suffren class mounts the Naval Cruise Missile (MdCN) launched from torpedo tubes without the need for a vertical launch system, unlike U.S. or Russian attack submarines. The MdCN allows attacking land targets at distances that, according to tests conducted with the frigate Aquitaine at the DGA range in Les Landes, exceed 1,000 kilometers. The Suffren was, in October 2020, the first French submarine to perform such a launch.
This capability gives France the ability to carry out surgical, precision strikes against strategically located land targets hundreds of kilometers inland, without the need to surface or reveal its position, cementing the Marine Nationale as the deadliest submarine force in the European Union.
Delivery to the DGA does not entail immediate active service; the submarine now enters an operational testing phase, with its integration into the fleet planned before the end of 2026. As part of that test voyage, the De Grasse made a stop in the United States for July 4 celebrations marking the country’s 250th independence anniversary, on July 4.
The De Grasse made there its first public appearance outside France. It occurred during the commemoration of the Battle of Chesapeake Bay. Let us recall that this naval battle, which took place on September 5, 1781, was decisive in the American War of Independence. There the fleet of British Admiral Thomas Graves and that of Lieutenant General of the Royal French Navy François Joseph Paul de Grasse faced off, since France militarily supported the American rebels against the United Kingdom. And it ended with the victory of… De Grasse.
Images | Naval Group, Mer et Marine
