The Qunqi Waterproof Phone Case is extremely nice to have around and more useful than most people would even think. I do not go out on a boat or swim often but when I do I will be sure to take this case with me simply for piece of mind.
The case is made of what feels like plastic and is large enough to house a nexus 6 or iPhone 6s Plus with no problem. It is sealed similar to a zip lock bag but on steroids. To seal it you squeeze the top together and then close two clamps. Also included with the case is a standard tether, an arm band, and universal mount that can attach to the case.
To initially test the case I stuffed it full of paper towels and submerged it in water for a half hour. After removing the case and drying off the outside I opened it. The paper towels on the inside were completely dry. Next I put my phone in the case and submerged it. All functions seemed to work just fine except for of course the fingerprint sensor. I was unable to test the rated 20m certification the packaging boasts, but my phone survived being fully submerged numerous times for extended periods.
If you are looking for a waterproof case for piece of mind while fishing or hunting, to swim with, run in the rain, or whatever other reason, I highly recommend the Quinqi Waterproof case which can be found here.