If I recall correctly, the crew of the X-6 or X-7 was captured and held aboard the Tirpitz while the timers for the charges they had set... counted down.
As a result of their discussion with the Germans, the Tirpitz was moved just enough, just in time... having had cold boilers.
The crew of the Tirpitz were able to see, hear, and feel the resultant explosion... right where their ship had been a bit earlier.
Was on the History or Military channel here.