https://www.amazon.com/gp/product/B074MFSHZC/ref=ewc_pr_img_8?smid=A2GWR9TI3GCQ47&psc=1

I did not purchase this yet, but had it in my cart to use for kayak camping. I wanted more of a backpack style bag so I can put it on my back to transport gear. I also intend to use it while walking out to fish on the marshes. I was going to get the 55 L, but they also have a 35 L, which is in between your range. The weight for the 55 L was only 3 lbs too, so it's a pretty light pack for being so cheap and made to be waterproof.