Supercavitating torpedoes can reach extreme underwater speeds by travelling inside a gas-filled cavity that sharply reduces their contact with water. Beyond torpedoes, supercavitating projectiles can streak through the water at blistering speeds to intercept naval mines, incoming torpedoes and u...
Source: [SCMP](https://www.scmp.com/news/china/science/article/3373333/chinese-engineers-reduce-cargo-ship-fuel-use-5-high-speed-torpedo-tech)