Supercavitation essentially creates a gas bubble around all but the very nose of a projectile in order to virtually eliminate water drag and achieve high speeds (possibly breaking the sound barrier). The technology is real and the applications range from peaceful ocean farming and exploration of Jupiter’s moon Europa to supercavitating weaponry like torpedoes and bullets. However, there appears to be plenty of obstacles (like steering, constantly changing pressures etc..) preventing such an occurrance. “Mastery of supercavitation could turn the quiet chess game of submarine warfare we know today into a mirror image of the hyper-kinetic world of aerial combat.” The cinematic possibilites alone make this phenomenon intriguing. Imagine Top Gun under water. Take note, Hollywood. This could make the basis for a great movie. [thanks to F2 and metascene]