The Hydro Tracker GPS from FINIS is a tracking, mapping, and performance-reporting accessory designed for open water swimmers. The GPS unit is designed to attach to the straps on swim goggles so that it sits on the back of the head to receive a constant signal. The Hydro Tracker GPS records data as you swim that can be used later to map your swim and analyze your route and rate. This data can be used to evaluate your performance and set new training goals, and you can share it with friends through CSV, KML, Google Earth, Facebook, and Twitter. The Hydro Tracker GPS also comes with a neoprene armband for use with hiking, biking, and other land-based sports. The Hydro Tracker GPS is $129.99 at FINIS.