Buy a drybag (in the Paddling section of their website) from REI. They will take abuse, and you can throw them in the back of the pick-up while driving and not worry about rain/snow making your clothes wet on the way to hunting.
Dry bags have their place but if you have to put damp clothing/boots in them for any length of time they're problematic. If you've got alot of gear get a bag in the 35 to 36 inch range. 30 inches is too small.
Red Oxx in MT make the best bags out there they will make a custom bag for you how you want it and they are guaranteed for life. http://www.redoxx.com/