Extending decoy pole, blind bag, blind chair, waterproof cell phone box.
I'd also consider a small folding saw for making blinds on the fly. You are also going to want either good gloves or a hand warmer that attaches to your waders. The list really goes on and on. Just some other things off the top of my head...
Decoy weights and line, I like my homemade keel grabbers
Face mask or face paint
Call lanyard - truthfully though, I'd worry about your decoys and spread first, then worry about calling.
Canoe roller if you will be using a canoe or kayak
And don't forget the TP in the blind bag.... You'll thank me later.