ASROC could be launched from a submarine against other submarines. And a missile can be launched over the horizon and change it's approach angle radically befo

ASROC could be launched from a submarine against other submarines. And a missile can be launched over the horizon and change it's approach angle radically before closing with the target. The Shkval basically can only travel in a straight line, and given its speed and short range the launching sub won't be able to do much evasion. The supercavitating torpedo is also traveling at high speed in a bubble of fizzing seawater, it must make a tremendous racket while approaching, there really isn't anything covert about it.