I'm not going to speak to specifics. Let's just say, you'd be surprised. It's more about the cutting force than it is say about the mass. Yes, a large boat will make even the dullest anchor a strong knife via force. But a small anchor that is sharpened could do the trick.
You don't need to split the wire in half. You merely need to expose it enough to cause it to go to ground with a significant enough amount.
The facility in question could see any boat on the water, and if a boat stayed over the lines too long. Authorities would have to be notified. After I left this exact thing happened by accident, and it was in an area where large boats did not enter due to the water being too shallow.
