Ever had one of those colder open water swim days when you would have liked an extra layer under your wetsuit? Behold the "wetskin", a sleeveless super-stretchable compression shirt that holds water against your torso a little better than your wetsuit does by itself. Alternatively, if you are finding the water getting too warm for your wetsuit, a wetskin can still provide a thin layer of insulation as well as protection from sun and sand on warmer days. Compression shirts like this one are made from 90% polimide/10% spandex fabric, using flat-lock stitching, providing superb form-fitting comfort. They have been used for all kinds of outdoor sports activities, such as cycling, running, yoga, and surfing. They are 100% breathable, quick-drying, anti-UV, and anti-bacterial, so their use in open water swimming is just the latest application of this high-tech fabric.