Stealth aircraft have been compared to submarines, and there are similarities between the two. Both depend on a smooth outside mould line for survival and carry their weapons internally, restricted by the ability to cut holes in the skin.
But then DCNS unveiled its SMX-24 concept for an advanced submarine at the Euronaval show in Paris, and turned those presuppositions on their head.
SMX-24 is a concept for a submarine that would be in service about 2020. Its size and capability fall between today's biggest diesel-electric boats and the smallest nukes: the 3450-ton boat would have an all fuel-cell propulsion system, would be capable of 20 kt submerged and could stay underwater for 30 days. The core vessel would have interchangeable modules for weapons or special forces equipment. The stub wings carry tip-mounted propulsors for high speeds - allowing the central pumpjet to be sized for cruise - and fighter-like pylons for fuel tanks - above the wings on the model - and weapons.
SMX-24 is a concept at the moment - but for how long, in the fast-changing submarine world? Last year at Euronaval, DCNS showed its SMX-23 concept for a small littoral submarine; it's here this year as a more detailed design named Andrasta, with six heavy weapons outside the pressure hull, and no on-board reloads.
pics: Bill Sweetman for DTI