I was referring more to small stealthy surface drones, like Ukraine's can carry a 200kg warhead and have a one-way range of 800km, but underwater drones... I mean, that's pretty much the literal definition of a torpedo, no? A modern Mark 48 torpedo has an estimated max range of 38 km at 55 kt or 50 km at 40 kt, probably even farther if you ran it slower... or if you weren't trying to fit it into a 21-inch-wide tube.