Unigear Waterproof Backpack 35L

I have been using this backpack daily for a few months now and it has been great. I can put my lunch box, a change of clothes and a pair of low profile sneakers in it without a problem. The internal pocket is great for storing important things I do not want to get wet but I also do not want under everything else. Has gone though rain, dust and dirt and held up well. I have not tried it with salt water, though. The external pocket is obviously not waterproof but has kept my wallet dry during a couple of walks in the rain. The built-in "whistle" on one of the straps is like 90% useless but I guess better than nothing. The straps can be adjusted a lot to fit well and hug your body, so that is good. Overall much better than I expected and very happy with my purchase, specially for the price and the discrete look of it.