If you want to see funny watch the look on the Iron mans face as he gets pulled over backwards while going for a refill in the backpack.This is not a onetime occurance I have witnessed while fishing snakes.
Get a large size Camelbak, you can fill it with enough beverage to last at least 1/2 of the tide. If you're rockhopping you don't need to mix the margarita before hand...it will mix its self