I don't think so. Actually it's saying that they managed to cross lines unnoticed but it was the case of fortune. And no one knows what it whould be if the real war starts. Generally it's the wide known fact that SSK could move silently. The process is quite complicated : at first they floated up, on the long distance from enemy, because the diesel engine can work only on the surface (it needs air to burn diesel fuel). They charged batteries on the surface and came on the distance of visibility - then they drowned and went on going on the electricity from batteries. When they could be discovered by acoustics, they simply stop the engines and move silently by flows or by inertion. It is several momoires from submariners, and I think that americans can show off with similar facts.