When the purchase agreement was signed, we were getting them for a song. It was the cost of fixing the bugs and updating them that cost so much. The value for money is most certainly debatable. However, it's almost pointless. It was a time of severe fiscal restraint which coincided with the end of the useful lives of our previous submarines. So, it was these boats or nothing. It's been a long, hard, expensive road to get them up to snuff. Anyway, the point behind linking the video, was to contrast the sound of a real torpedo detonation with what you might hear from Hollywood, not to discuss the merits of the boat that fired it.