Let's see... a former boss owned an Arneson, basically a jet engine-driven screw on a catamaran hull. My wife and I got a ride in it once; we were cruising at 120 MPH (193 KPH if I did that right) and the rooster tail was, oh... hell, there's a picture (though not of us) here: http://gallery.nonken.net/jeff_misc/9507_G We went from one end of Folsom Lake to the other in two minutes flat.
OK, now. Toss your tangled web over that and get it caught in the screw. One of two things is likely to happen:
1) The freakin' jet engine -- and I am not exaggerating, the whine was killer even with the ear protection -- will laugh like hell at your pretentious pathetic attempt and shred it like cheese.
2) Your net is tougher than hell and it actually stops the screw. All that torque has to go somewhere. Let's see. Hmm. In my mind's eye I see... the engine turns one way, the back end of the boat turns the other, the hull shatters, the passengers and various parts of the boat go flying in various directions (but still with a rather impressive horizontal vector in the original direction). I can practically guarantee no survivors and the corpses may not even arrive in one piece each. Any nearby boats will be in great danger. I don't want to predict any Hollywood-style explosions but what happens when several gallons of kerosene get tossed on the water with that screaming hot engine that's still trying to come apart. ... Unless it's already come apart, dumping burning fuel and shrapnel.
I'm sure glad this is non-lethal, hmm? Let's talk "unintended consequences" here.