I dont know about the 199 feet thing. Seems kind of deep or too close... whatever.
I do know that when you launch one you want to make sure your making less 'noise' than your intended target. If you are and it misses said target chances are its going to target you. I believe it even tells you this in the description text of the weapon.
Lastley the main use for those types of torpedoes is to attack the pesky destroyers as already mentioned. Its fairly easy to hit a merchant doing 8 knots in a straight line. DD's steaming at 12 knots and constantly changing courses is another matter.
Keep better track of your munitions sailor
