this kind of reminds me of the situation Trey and I had with the parasailing boat off of west palm during the Tybee.

We had established a course to stay clear of the parasail boat, it changed course and crossed in front of us with less than 50 feet to go, we were balls-out flying downwind... only thing to do to avoid entangling a parasailer was to crash-gybe and capsize to be sure to keep the mast out of the tow-line (which was very low to the water since the parasailer lost speed and therefore altitude).

Tempers were hot on our side but really there was no recourse other than to swallow our pride, right the boat, and keep going.

Its unfortunate that the fisher wasn't aware of the rules of the road. (And poo-hoo if they consider a trolling fishing boat "encumbered")