The easy-to-use Garmin Foretrex 101 GPS wrist-top navigator weighing in at a mere 2.6 oz. is lighter than many sport watches Simple, single-hand operational system features six ergonomically situated buttons that intuitively guide you through functions. Navigate for up to 15 hours on two AAA batteries based on typical use. WAAS Wide Area Augmentation System enabled receiver delivers accuracy within 3 meters or better. For the mariner, sail race feature allows you to configure the start countdown sequence with audible alerts at each start phase. View route and follow it back with Garmins exclusive TracBack feature. Navigate 20 reversible routes stores 500 waypoints with name and graphic symbols and 10,000 trackpoints. Trip computer calculates current, average and maximum speed also tracks trip time and calculates distance. Computer-compatible design allows you to load waypoints and routes directly from your computer cable sold separately. Waterproof construction, meets IEC 529 lPX7 standard functional after 30 min. submerged in 1m of water. High-contrast screen with bright LED backlighting for use in low light.