E-Case iSeries Shockproof Protective Case for iPod & iPhone 5 with 3.5mm Headphone Jack - Perfect for Travel, Workouts & Everyday Use

This is the ideal case for skiing. First of all, it fit my iPhone 5s while still in its hard case, which was a must for me. Note that my hard case is a slimline type, not an Otterbox style. So this avoided the hassle of switching cases - I could just drop my phone into this one as is. It was also easy to get in and out, which can be an issue with these waterproof cases sometimes. I've had a bunch of them and this is by far the best in terms of ease of use, and also the nicest in terms of style. I love the light weight and slim profile of this case. It doesn't have the bulky hard plastic clamp that others do, which makes it much easier to carry inside a jacket. I put it on a lanyard and attached it via audio cable to my ski helmet, and it worked a treat. It protected my phone from the snow perfectly, and the audio jack was very handy. I haven't yet tried it for swimming, so I can't speak to its effectiveness when fully submerged in water, but this is hands down the best case for skiing that I have found.