Supercavitating underwater bullets
Regular bullets decelerate so quickly in water that they only make it a few feet, which is why diving into a conveniently located pool or waterway when under fire from assassins can be such a good idea. But Norway’s DSG has used the drag-reducing abilities of supercavitation to produce some truly extraordinary projectiles that’ll hit submerged targets up to 60 m (200 ft) away, opening up some interesting new mission capabilities.
Supercavitation refers to designs that wrap an underwater projectile in a bubble of air to vastly reduce skin friction drag. It’s been used on torpedoes, allowing them to move some five times faster through the water than regular ones, as well as on propellers and some pretty wild boat designs, and it’s being investigated as a potential way to produce ultra-fast submarines.