I see four torpedoes heading for the red ship which has the white X centered on it.
All 4 running hot straight and normal.
Yet they somehow pass right though the White X ,centered on the red ship marker without a hit. No call of "thats a dud sir".
So what happens in those cases? Obviously it is too late to go watch on external view if they ran too deeply....and in any event I always set 2 out of four to run shallow to compensate for the expected deep runner.