I bought Patagonia's Stormfront backpack. Ever the deal finder, I bought one on sale on the Patagonia website for $110. My bro and I even made a little pocket cash selling some of the packs on eBay with a slight positive margin.
It is pricey but I am planning on using it as a flats pack (it holds a hydration bladder (sold separately) and as a deck bag for my kayak. I plan on outfitting the chest/sternum strap with a holder for a fly box so that I can minimize the need to get stuff out of the pack.
When I fish I always wade too deeply and get all of the junk in my William Joseph bandolier wet. With the waterproof Patagonia pack I can dip it in the water and the stuff in the bag will not get wet. Therefore I will not have to worry about corrosion on all of the stuff in the bag. I am trying to minimize the amount of rinsing and clean up after a saltwater outing. Soak the bag in water after use, rinse it, and I am done.
The pack will also make a great deck bag given proper rigging on the deck of my yak. So, it is a 2 for 1 pack in my world - that is how I justified the price.
The waterproof zipper is a wee bit tough to open and close and I will keep you posted as to how it holds up over time.