Dear Customer, here is the height in inches for all of the various sizes.5L: 14.9inches10L: 19.2inches20L: 22.8inches30L: 25.5inches40L: 27.5inches
I don't think I would do that, I think a good dunking in the water you would be more than fine, even for an extended time. Towing it not sure about that, could put in tub to try it. We love ours, they are very well made, have no issues often, tied to deck of Kayak and takes good bouts of water with no issues.
Yes, the ipx of the dry bag is ipx 4 and the waterproof phone case is ipx 8.
Depends on whether you want the camera to stay dry or not. It would keep the camera attached to your kayak, but the camera would get wet. When I floated the calm river with the bag everything in the bag was soaked. Luckily the phones were already waterproof and the wallets dried out.