I got this for paddle boarding, kayaking and tubing. The size is great and I love the backpack straps. Since there isn't any 'ziplock' style seal before you roll it and it's just compression based, it deflates air as it goes. I ended up putting my keys and wallet into my 2ltr ziplock style dry bag and putting that inside this 20ltr one. I haven't ended up getting puddles inside, but there are a few droplets on the inside of the bag by the end of the trip. I would say it does what it needs to do,See full review