I prefer Camelbaks over and above! They hold a large amount of water, they transport it comfortably, the water is readily accessible, it doesn't slosh or bounce on your hip, and many models make great backpacks. They are available in many sizes. I have several models; one will hold 3 x 100 oz. bladders. With 300 oz. of water you should be good to go for quite some time.

One caveat... ensure that you get the newer models with the large opening. This makes it easy to clean and fill. I also prefer the military models that have a protective covering over the tube so that it doesn't get shredded when going through brush. You can buy the bladder or tube sock separately and add it to other models.

Although you can’t boil water in your Camelbak...