I'm curious to know how it was done in real life, you see. Because to me thus far it appears a death scenario either way!!! Mines, ok, they'd have maps of mine fields or something like that, but the nets are naturally there in harbour. I suspect it's preciesly for that reason why the harbour sneaks (into the miliary bases) were oh so rare. Because in real life, you can't see what's ahead using the periscope. I suspect going 2knots 3metres from the ground would also stir up some silt and the vizibility would be thrown away. And to that doing it at night - forget it about!!
The techique of following a ship is interesting, but you'd have to see how it moves, and hope it moves slow. 8knts behind it can still be dangerous.
What about putting a torpedo set to impact detonation into the net? Anyone tried that?
Until than, we have the external cam, so we can see the prize and hope we can make it and still have fun!