 Some torpedoes—like the Russian VA-111 Shkval, Iranian Hoot, and German —use supercavitation to increase speed to over .Torpedoes that don't use supercavitation, such as the American Mark 48 and British Spearfish, are limited to under , though manufacturers and the military don't always release exact figures.Torpedoes may be aimed at the target and fired unguided, similarly to a traditional artillery shell, or they may be guided onto the target.