Rugged Handheld This handheld is water-resistant (IPX7) with a high-resolution color display you can read in the sun. The glass is even scratch-resistant and fogproof. Designed To Float If rough waters come and the handheld goes overboard, don’t worry. This device floats. Battery Life User-replaceable AA batteries (not included) provide up to 19 hours of battery life in GPS tracking mode. Accurate Tracking With support for multiple satellite constellations — such as GPS, GLONASS, Galileo, QZSS and SBAS — you’ll get accurate, reliable tracking and positioning around the world. Increased Memory More memory than previous models means you can save and track 10,000 waypoints, 250 routes and 300 fitness activity files. Built-In Compass The 3-axis tilt-compensated electronic compass shows your heading — even while the boat is standing still. Bluechart Coverage Preloaded BlueChart g3 coastal charts (GPSMAP 79sc only) give you leading-edge coverage, clarity and detail with integrated Garmin and Navionics data.