Forgot to mention for those times requiring extra water, besides the water bottle pouch on the one side, the Lowepro has a flat compartment for the Camelbak water bladder and a slot to feed the hydration tubing through to the outside just like the Camelbak. It also has a pull out water proof cover that encloses the whole pack if you get caught in the rain. We also have two Camelbak packs that we use at times. Now I think it's time to get the vest
You can never be too prepared.
Dave