The K-21 submarine is a Russian Project 641 diesel-electric submarine, part of the Soviet Navy fleet. Launched in 1953, it was designed for anti-submarine warfare and reconnaissance missions. The K-21 features a length of 90 meters and can operate at depths of up to 300 meters. Equipped with torpedoes and mines, the K-21 has been a significant asset in naval operations. It is powered by diesel engines and can stay submerged for extended periods. The submarine represents a key part of Cold War naval strategy, showcasing the technological advancements of its time.