Fishing equipment: At the very least, you'll need a dipnet if you want to go dipnetting. 8-)
Safety equipment: Depending where and how you fish, you might also want to bring
Other: after fishing, you'll need:
Bring a boat, boat gas, spare dipnets, tents, fillet knives, sharpening steels, sleeping bags, beer, more ice than you think you'll ever need What advanced type of equipment could I bring that would be useful?